1151 lines
38 KiB
C
1151 lines
38 KiB
C
//*****************************************************************************
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//
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// ssi.c - Driver for Synchronous Serial Interface.
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//
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// Copyright (c) 2005-2017 Texas Instruments Incorporated. All rights reserved.
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// Software License Agreement
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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//
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// Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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//
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// Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the
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// distribution.
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//
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// Neither the name of Texas Instruments Incorporated nor the names of
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// its contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// This is part of revision 2.1.4.178 of the Tiva Peripheral Driver Library.
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//
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//*****************************************************************************
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//*****************************************************************************
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//
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//! \addtogroup ssi_api
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//! @{
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//
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//*****************************************************************************
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#include <stdbool.h>
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#include <stdint.h>
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#include "inc/hw_ints.h"
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#include "inc/hw_memmap.h"
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#include "inc/hw_ssi.h"
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#include "inc/hw_sysctl.h"
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#include "inc/hw_types.h"
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#include "driverlib/debug.h"
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#include "driverlib/interrupt.h"
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#include "driverlib/ssi.h"
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//*****************************************************************************
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//
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// A mapping of timer base address to interrupt number.
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//
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//*****************************************************************************
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static const uint32_t g_ppui32SSIIntMap[][2] =
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{
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{ SSI0_BASE, INT_SSI0_TM4C123 },
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{ SSI1_BASE, INT_SSI1_TM4C123 },
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{ SSI2_BASE, INT_SSI2_TM4C123 },
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{ SSI3_BASE, INT_SSI3_TM4C123 },
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};
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static const uint_fast8_t g_ui8SSIIntMapRows =
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sizeof(g_ppui32SSIIntMap) / sizeof(g_ppui32SSIIntMap[0]);
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static const uint32_t g_ppui32SSIIntMapSnowflake[][2] =
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{
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{ SSI0_BASE, INT_SSI0_TM4C129 },
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{ SSI1_BASE, INT_SSI1_TM4C129 },
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{ SSI2_BASE, INT_SSI2_TM4C129 },
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{ SSI3_BASE, INT_SSI3_TM4C129 },
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};
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static const uint_fast8_t g_ui8SSIIntMapSnowflakeRows =
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sizeof(g_ppui32SSIIntMapSnowflake) / sizeof(g_ppui32SSIIntMapSnowflake[0]);
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//*****************************************************************************
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//
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//! \internal
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//! Checks an SSI base address.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//!
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//! This function determines if a SSI module base address is valid.
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//!
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//! \return Returns \b true if the base address is valid and \b false
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//! otherwise.
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//
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//*****************************************************************************
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#ifdef DEBUG
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static bool
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_SSIBaseValid(uint32_t ui32Base)
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{
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return((ui32Base == SSI0_BASE) || (ui32Base == SSI1_BASE) ||
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(ui32Base == SSI2_BASE) || (ui32Base == SSI3_BASE));
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}
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#endif
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//*****************************************************************************
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//
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//! Returns the interrupt number of SSI module .
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//!
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//! \param ui32Base is the base address of the SSI module.
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//!
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//! This function returns the interrupt number for the SSI module with the base
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//! address passed in the \e ui32Base parameter.
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//!
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//! \return Returns an SSI interrupt number, or 0 if the interrupt does not
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//! exist.
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//
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//*****************************************************************************
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static uint32_t
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_SSIIntNumberGet(uint32_t ui32Base)
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{
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uint_fast8_t ui8Idx, ui8Rows;
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const uint32_t (*ppui32SSIIntMap)[2];
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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ppui32SSIIntMap = g_ppui32SSIIntMap;
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ui8Rows = g_ui8SSIIntMapRows;
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if(CLASS_IS_TM4C129)
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{
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ppui32SSIIntMap = g_ppui32SSIIntMapSnowflake;
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ui8Rows = g_ui8SSIIntMapSnowflakeRows;
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}
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//
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// Loop through the table that maps SSI base addresses to interrupt
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// numbers.
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//
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for(ui8Idx = 0; ui8Idx < ui8Rows; ui8Idx++)
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{
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//
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// See if this base address matches.
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//
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if(ppui32SSIIntMap[ui8Idx][0] == ui32Base)
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{
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//
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// Return the corresponding interrupt number.
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//
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return(ppui32SSIIntMap[ui8Idx][1]);
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}
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}
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//
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// The base address could not be found, so return an error.
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//
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return(0);
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}
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//*****************************************************************************
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//
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//! Configures the synchronous serial interface.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//! \param ui32SSIClk is the rate of the clock supplied to the SSI module.
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//! \param ui32Protocol specifies the data transfer protocol.
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//! \param ui32Mode specifies the mode of operation.
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//! \param ui32BitRate specifies the clock rate.
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//! \param ui32DataWidth specifies number of bits transferred per frame.
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//!
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//! This function configures the synchronous serial interface. It sets
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//! the SSI protocol, mode of operation, bit rate, and data width.
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//!
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//! The \e ui32Protocol parameter defines the data frame format. The
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//! \e ui32Protocol parameter can be one of the following values:
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//! \b SSI_FRF_MOTO_MODE_0, \b SSI_FRF_MOTO_MODE_1, \b SSI_FRF_MOTO_MODE_2,
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//! \b SSI_FRF_MOTO_MODE_3, \b SSI_FRF_TI, or \b SSI_FRF_NMW. Note that
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//! the \b SSI_FRF_NMW option is only available on some devices. Refer to the
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//! device data sheet to determine if the Microwire format is supported on
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//! a particular device. The Motorola frame formats encode the following
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//! polarity and phase configurations:
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//!
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//! <pre>
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//! Polarity Phase Mode
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//! 0 0 SSI_FRF_MOTO_MODE_0
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//! 0 1 SSI_FRF_MOTO_MODE_1
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//! 1 0 SSI_FRF_MOTO_MODE_2
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//! 1 1 SSI_FRF_MOTO_MODE_3
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//! </pre>
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//!
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//! The \e ui32Mode parameter defines the operating mode of the SSI module.
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//! The SSI module can operate as a master or slave; if it is a slave, the SSI
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//! can be configured to disable output on its serial output line. The
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//! \e ui32Mode parameter can be one of the following values:
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//! \b SSI_MODE_MASTER, \b SSI_MODE_SLAVE, or \b SSI_MODE_SLAVE_OD.
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//!
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//! The \e ui32BitRate parameter defines the bit rate for the SSI. This bit
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//! rate must satisfy the following clock ratio criteria:
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//!
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//! - FSSI >= 2 * bit rate (master mode)
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//! - FSSI >= 12 * bit rate (slave modes)
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//!
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//! where FSSI is the frequency of the clock supplied to the SSI module. Note
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//! that there are frequency limits for FSSI that are described in the Bit Rate
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//! Generation section of the SSI chapter in the data sheet.
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//!
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//! The \e ui32DataWidth parameter defines the width of the data transfers and
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//! can be a value between 4 and 16, inclusive.
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//!
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//! The peripheral clock is the same as the processor clock. The frequency of
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//! the system clock is the value returned by SysCtlClockGet() for TM4C123x
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//! devices or the value returned by SysCtlClockFreqSet() for TM4C129x devices,
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//! or it can be explicitly hard coded if it is constant and known (to save the
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//! code/execution overhead of a call to SysCtlClockGet() or fetch of the
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//! variable call holding the return value of SysCtlClockFreqSet()).
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIConfigSetExpClk(uint32_t ui32Base, uint32_t ui32SSIClk,
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uint32_t ui32Protocol, uint32_t ui32Mode,
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uint32_t ui32BitRate, uint32_t ui32DataWidth)
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{
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uint32_t ui32MaxBitRate;
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uint32_t ui32RegVal;
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uint32_t ui32PreDiv;
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uint32_t ui32SCR;
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uint32_t ui32SPH_SPO;
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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ASSERT((ui32Protocol == SSI_FRF_MOTO_MODE_0) ||
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(ui32Protocol == SSI_FRF_MOTO_MODE_1) ||
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(ui32Protocol == SSI_FRF_MOTO_MODE_2) ||
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(ui32Protocol == SSI_FRF_MOTO_MODE_3) ||
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(ui32Protocol == SSI_FRF_TI) ||
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(ui32Protocol == SSI_FRF_NMW));
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ASSERT((ui32Mode == SSI_MODE_MASTER) ||
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(ui32Mode == SSI_MODE_SLAVE));
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ASSERT(((ui32Mode == SSI_MODE_MASTER) &&
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(ui32BitRate <= (ui32SSIClk / 2))) ||
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((ui32Mode != SSI_MODE_MASTER) &&
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(ui32BitRate <= (ui32SSIClk / 12))));
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ASSERT((ui32SSIClk / ui32BitRate) <= (254 * 256));
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ASSERT((ui32DataWidth >= 4) && (ui32DataWidth <= 16));
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//
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// Set the mode.
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//
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ui32RegVal = (ui32Mode == SSI_MODE_MASTER) ? 0 : SSI_CR1_MS;
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HWREG(ui32Base + SSI_O_CR1) = ui32RegVal;
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//
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// Set the clock predivider.
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//
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ui32MaxBitRate = ui32SSIClk / ui32BitRate;
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ui32PreDiv = 0;
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do
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{
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ui32PreDiv += 2;
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ui32SCR = (ui32MaxBitRate / ui32PreDiv) - 1;
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}
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while(ui32SCR > 255);
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HWREG(ui32Base + SSI_O_CPSR) = ui32PreDiv;
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//
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// Set protocol and clock rate.
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//
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ui32SPH_SPO = (ui32Protocol & 3) << 6;
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ui32Protocol &= SSI_CR0_FRF_M;
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ui32RegVal = (ui32SCR << 8) | ui32SPH_SPO | ui32Protocol |
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(ui32DataWidth - 1);
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HWREG(ui32Base + SSI_O_CR0) = ui32RegVal;
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}
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//*****************************************************************************
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//
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//! Enables the synchronous serial interface.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//!
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//! This function enables operation of the synchronous serial interface. The
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//! synchronous serial interface must be configured before it is enabled.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIEnable(uint32_t ui32Base)
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{
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Read-modify-write the enable bit.
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//
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HWREG(ui32Base + SSI_O_CR1) |= SSI_CR1_SSE;
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}
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//*****************************************************************************
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//
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//! Disables the synchronous serial interface.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//!
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//! This function disables operation of the synchronous serial interface.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIDisable(uint32_t ui32Base)
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{
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Read-modify-write the enable bit.
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//
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HWREG(ui32Base + SSI_O_CR1) &= ~(SSI_CR1_SSE);
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}
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//*****************************************************************************
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//
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//! Registers an interrupt handler for the synchronous serial interface.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//! \param pfnHandler is a pointer to the function to be called when the
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//! synchronous serial interface interrupt occurs.
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//!
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//! This function registers the handler to be called when an SSI interrupt
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//! occurs. This function enables the global interrupt in the interrupt
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//! controller; specific SSI interrupts must be enabled via SSIIntEnable(). If
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//! necessary, it is the interrupt handler's responsibility to clear the
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//! interrupt source via SSIIntClear().
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//!
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//! \sa IntRegister() for important information about registering interrupt
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//! handlers.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIIntRegister(uint32_t ui32Base, void (*pfnHandler)(void))
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{
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uint32_t ui32Int;
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Determine the interrupt number based on the SSI module.
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//
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ui32Int = _SSIIntNumberGet(ui32Base);
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ASSERT(ui32Int != 0);
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//
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// Register the interrupt handler, returning an error if an error occurs.
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//
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IntRegister(ui32Int, pfnHandler);
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//
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// Enable the synchronous serial interface interrupt.
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//
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IntEnable(ui32Int);
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}
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//*****************************************************************************
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//
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//! Unregisters an interrupt handler for the synchronous serial interface.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//!
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//! This function clears the handler to be called when an SSI interrupt
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//! occurs. This function also masks off the interrupt in the interrupt
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//! controller so that the interrupt handler no longer is called.
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//!
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//! \sa IntRegister() for important information about registering interrupt
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//! handlers.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIIntUnregister(uint32_t ui32Base)
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{
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uint32_t ui32Int;
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Determine the interrupt number based on the SSI module.
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//
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ui32Int = _SSIIntNumberGet(ui32Base);
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ASSERT(ui32Int != 0);
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//
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// Disable the interrupt.
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//
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IntDisable(ui32Int);
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//
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// Unregister the interrupt handler.
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//
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IntUnregister(ui32Int);
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}
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//*****************************************************************************
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//
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//! Enables individual SSI interrupt sources.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//! \param ui32IntFlags is a bit mask of the interrupt sources to be enabled.
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//!
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//! This function enables the indicated SSI interrupt sources. Only the
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//! sources that are enabled can be reflected to the processor interrupt;
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//! disabled sources have no effect on the processor. The \e ui32IntFlags
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//! parameter can be any of the \b SSI_TXFF, \b SSI_RXFF, \b SSI_RXTO, or
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//! \b SSI_RXOR values.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIIntEnable(uint32_t ui32Base, uint32_t ui32IntFlags)
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{
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Enable the specified interrupts.
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//
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HWREG(ui32Base + SSI_O_IM) |= ui32IntFlags;
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}
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//*****************************************************************************
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//
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//! Disables individual SSI interrupt sources.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//! \param ui32IntFlags is a bit mask of the interrupt sources to be disabled.
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//!
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//! This function disables the indicated SSI interrupt sources. The
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//! \e ui32IntFlags parameter can be any of the \b SSI_TXFF, \b SSI_RXFF,
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//! \b SSI_RXTO, or \b SSI_RXOR values.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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SSIIntDisable(uint32_t ui32Base, uint32_t ui32IntFlags)
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{
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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//
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// Disable the specified interrupts.
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//
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HWREG(ui32Base + SSI_O_IM) &= ~(ui32IntFlags);
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}
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|
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//*****************************************************************************
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//
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//! Gets the current interrupt status.
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//!
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//! \param ui32Base specifies the SSI module base address.
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//! \param bMasked is \b false if the raw interrupt status is required or
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//! \b true if the masked interrupt status is required.
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//!
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//! This function returns the interrupt status for the SSI module. Either the
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//! raw interrupt status or the status of interrupts that are allowed to
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//! reflect to the processor can be returned.
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//!
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//! \return The current interrupt status, enumerated as a bit field of
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//! \b SSI_TXFF, \b SSI_RXFF, \b SSI_RXTO, and \b SSI_RXOR.
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//
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//*****************************************************************************
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uint32_t
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SSIIntStatus(uint32_t ui32Base, bool bMasked)
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{
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//
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// Check the arguments.
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//
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ASSERT(_SSIBaseValid(ui32Base));
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|
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//
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// Return either the interrupt status or the raw interrupt status as
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// requested.
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//
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if(bMasked)
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{
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return(HWREG(ui32Base + SSI_O_MIS));
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}
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else
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{
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return(HWREG(ui32Base + SSI_O_RIS));
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}
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}
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|
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//*****************************************************************************
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//
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|
//! Clears SSI interrupt sources.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param ui32IntFlags is a bit mask of the interrupt sources to be cleared.
|
|
//!
|
|
//! This function clears the specified SSI interrupt sources so that they no
|
|
//! longer assert. This function must be called in the interrupt handler to
|
|
//! keep the interrupts from being triggered again immediately upon exit. The
|
|
//! \e ui32IntFlags parameter can consist of either or both the \b SSI_RXTO and
|
|
//! \b SSI_RXOR values.
|
|
//!
|
|
//! \note Because there is a write buffer in the Cortex-M processor, it may
|
|
//! take several clock cycles before the interrupt source is actually cleared.
|
|
//! Therefore, it is recommended that the interrupt source be cleared early in
|
|
//! the interrupt handler (as opposed to the very last action) to avoid
|
|
//! returning from the interrupt handler before the interrupt source is
|
|
//! actually cleared. Failure to do so may result in the interrupt handler
|
|
//! being immediately reentered (because the interrupt controller still sees
|
|
//! the interrupt source asserted).
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIIntClear(uint32_t ui32Base, uint32_t ui32IntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Clear the requested interrupt sources.
|
|
//
|
|
HWREG(ui32Base + SSI_O_ICR) = ui32IntFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Puts a data element into the SSI transmit FIFO.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param ui32Data is the data to be transmitted over the SSI interface.
|
|
//!
|
|
//! This function places the supplied data into the transmit FIFO of the
|
|
//! specified SSI module. If there is no space available in the transmit FIFO,
|
|
//! this function waits until there is space available before returning.
|
|
//!
|
|
//! \note The upper 32 - N bits of \e ui32Data are discarded by the hardware,
|
|
//! where N is the data width as configured by SSIConfigSetExpClk(). For
|
|
//! example, if the interface is configured for 8-bit data width, the upper 24
|
|
//! bits of \e ui32Data are discarded.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIDataPut(uint32_t ui32Base, uint32_t ui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Data & (0xfffffffe << (HWREG(ui32Base + SSI_O_CR0) &
|
|
SSI_CR0_DSS_M))) == 0);
|
|
|
|
//
|
|
// Wait until there is space.
|
|
//
|
|
while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF))
|
|
{
|
|
}
|
|
|
|
//
|
|
// Write the data to the SSI.
|
|
//
|
|
HWREG(ui32Base + SSI_O_DR) = ui32Data;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Puts a data element into the SSI transmit FIFO.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param ui32Data is the data to be transmitted over the SSI interface.
|
|
//!
|
|
//! This function places the supplied data into the transmit FIFO of the
|
|
//! specified SSI module. If there is no space in the FIFO, then this function
|
|
//! returns a zero.
|
|
//!
|
|
//! \note The upper 32 - N bits of \e ui32Data are discarded by the hardware,
|
|
//! where N is the data width as configured by SSIConfigSetExpClk(). For
|
|
//! example, if the interface is configured for 8-bit data width, the upper 24
|
|
//! bits of \e ui32Data are discarded.
|
|
//!
|
|
//! \return Returns the number of elements written to the SSI transmit FIFO.
|
|
//
|
|
//*****************************************************************************
|
|
int32_t
|
|
SSIDataPutNonBlocking(uint32_t ui32Base, uint32_t ui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Data & (0xfffffffe << (HWREG(ui32Base + SSI_O_CR0) &
|
|
SSI_CR0_DSS_M))) == 0);
|
|
|
|
//
|
|
// Check for space to write.
|
|
//
|
|
if(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF)
|
|
{
|
|
HWREG(ui32Base + SSI_O_DR) = ui32Data;
|
|
return(1);
|
|
}
|
|
else
|
|
{
|
|
return(0);
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets a data element from the SSI receive FIFO.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param pui32Data is a pointer to a storage location for data that was
|
|
//! received over the SSI interface.
|
|
//!
|
|
//! This function gets received data from the receive FIFO of the specified
|
|
//! SSI module and places that data into the location specified by the
|
|
//! \e pui32Data parameter. If there is no data available, this function waits
|
|
//! until data is received before returning.
|
|
//!
|
|
//! \note Only the lower N bits of the value written to \e pui32Data contain
|
|
//! valid data, where N is the data width as configured by
|
|
//! SSIConfigSetExpClk(). For example, if the interface is configured for
|
|
//! 8-bit data width, only the lower 8 bits of the value written to
|
|
//! \e pui32Data contain valid data.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIDataGet(uint32_t ui32Base, uint32_t *pui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Wait until there is data to be read.
|
|
//
|
|
while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_RNE))
|
|
{
|
|
}
|
|
|
|
//
|
|
// Read data from SSI.
|
|
//
|
|
*pui32Data = HWREG(ui32Base + SSI_O_DR);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets a data element from the SSI receive FIFO.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param pui32Data is a pointer to a storage location for data that was
|
|
//! received over the SSI interface.
|
|
//!
|
|
//! This function gets received data from the receive FIFO of the specified SSI
|
|
//! module and places that data into the location specified by the \e ui32Data
|
|
//! parameter. If there is no data in the FIFO, then this function returns a
|
|
//! zero.
|
|
//!
|
|
//! \note Only the lower N bits of the value written to \e pui32Data contain
|
|
//! valid data, where N is the data width as configured by
|
|
//! SSIConfigSetExpClk(). For example, if the interface is configured for
|
|
//! 8-bit data width, only the lower 8 bits of the value written to
|
|
//! \e pui32Data contain valid data.
|
|
//!
|
|
//! \return Returns the number of elements read from the SSI receive FIFO.
|
|
//
|
|
//*****************************************************************************
|
|
int32_t
|
|
SSIDataGetNonBlocking(uint32_t ui32Base, uint32_t *pui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Check for data to read.
|
|
//
|
|
if(HWREG(ui32Base + SSI_O_SR) & SSI_SR_RNE)
|
|
{
|
|
*pui32Data = HWREG(ui32Base + SSI_O_DR);
|
|
return(1);
|
|
}
|
|
else
|
|
{
|
|
return(0);
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Enables SSI DMA operation.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//! \param ui32DMAFlags is a bit mask of the DMA features to enable.
|
|
//!
|
|
//! This function enables the specified SSI DMA features. The SSI can be
|
|
//! configured to use DMA for transmit and/or receive data transfers.
|
|
//! The \e ui32DMAFlags parameter is the logical OR of any of the following
|
|
//! values:
|
|
//!
|
|
//! - SSI_DMA_RX - enable DMA for receive
|
|
//! - SSI_DMA_TX - enable DMA for transmit
|
|
//!
|
|
//! \note The uDMA controller must also be set up before DMA can be used
|
|
//! with the SSI.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIDMAEnable(uint32_t ui32Base, uint32_t ui32DMAFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Set the requested bits in the SSI DMA control register.
|
|
//
|
|
HWREG(ui32Base + SSI_O_DMACTL) |= ui32DMAFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Disables SSI DMA operation.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//! \param ui32DMAFlags is a bit mask of the DMA features to disable.
|
|
//!
|
|
//! This function is used to disable SSI DMA features that were enabled
|
|
//! by SSIDMAEnable(). The specified SSI DMA features are disabled. The
|
|
//! \e ui32DMAFlags parameter is the logical OR of any of the following values:
|
|
//!
|
|
//! - SSI_DMA_RX - disable DMA for receive
|
|
//! - SSI_DMA_TX - disable DMA for transmit
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIDMADisable(uint32_t ui32Base, uint32_t ui32DMAFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Clear the requested bits in the SSI DMA control register.
|
|
//
|
|
HWREG(ui32Base + SSI_O_DMACTL) &= ~ui32DMAFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Determines whether the SSI transmitter is busy or not.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//!
|
|
//! This function allows the caller to determine whether all transmitted bytes
|
|
//! have cleared the transmitter hardware. If \b false is returned, then the
|
|
//! transmit FIFO is empty and all bits of the last transmitted word have left
|
|
//! the hardware shift register.
|
|
//!
|
|
//! \return Returns \b true if the SSI is transmitting or \b false if all
|
|
//! transmissions are complete.
|
|
//
|
|
//*****************************************************************************
|
|
bool
|
|
SSIBusy(uint32_t ui32Base)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Determine if the SSI is busy.
|
|
//
|
|
return((HWREG(ui32Base + SSI_O_SR) & SSI_SR_BSY) ? true : false);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Sets the data clock source for the specified SSI peripheral.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//! \param ui32Source is the baud clock source for the SSI.
|
|
//!
|
|
//! This function allows the baud clock source for the SSI to be selected.
|
|
//! The possible clock source are the system clock (\b SSI_CLOCK_SYSTEM) or
|
|
//! the precision internal oscillator (\b SSI_CLOCK_PIOSC).
|
|
//!
|
|
//! Changing the baud clock source changes the data rate generated by the
|
|
//! SSI. Therefore, the data rate should be reconfigured after any change to
|
|
//! the SSI clock source.
|
|
//!
|
|
//! \note The ability to specify the SSI baud clock source varies with the
|
|
//! Tiva part and SSI in use. Please consult the data sheet for the part
|
|
//! in use to determine whether this support is available.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIClockSourceSet(uint32_t ui32Base, uint32_t ui32Source)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Source == SSI_CLOCK_SYSTEM) ||
|
|
(ui32Source == SSI_CLOCK_PIOSC));
|
|
|
|
//
|
|
// Set the SSI clock source.
|
|
//
|
|
HWREG(ui32Base + SSI_O_CC) = ui32Source;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the data clock source for the specified SSI peripheral.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//!
|
|
//! This function returns the data clock source for the specified SSI.
|
|
//!
|
|
//! \note The ability to specify the SSI data clock source varies with the
|
|
//! Tiva part and SSI in use. Please consult the data sheet for the part
|
|
//! in use to determine whether this support is available.
|
|
//!
|
|
//! \return Returns the current clock source, which is either
|
|
//! \b SSI_CLOCK_SYSTEM or \b SSI_CLOCK_PIOSC.
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
SSIClockSourceGet(uint32_t ui32Base)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Return the SSI clock source.
|
|
//
|
|
return(HWREG(ui32Base + SSI_O_CC));
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Selects the advanced mode of operation for the SSI module.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//! \param ui32Mode is the mode of operation to use.
|
|
//!
|
|
//! This function selects the mode of operation for the SSI module, which is
|
|
//! needed when using the advanced operation modes (Bi- or Quad-SPI). One of
|
|
//! the following modes can be selected:
|
|
//!
|
|
//! - \b SSI_ADV_MODE_LEGACY - Disables the advanced modes of operation,
|
|
//! resulting in legacy, or backwards-compatible, operation. When this mode
|
|
//! is selected, it is not valid to switch to Bi- or Quad-SPI operation.
|
|
//! This mode is the default.
|
|
//! - \b SSI_ADV_MODE_WRITE - The advanced mode of operation where data is only
|
|
//! written to the slave; any data clocked in via the \b SSIRx pin is thrown
|
|
//! away (instead of being placed into the SSI Rx FIFO).
|
|
//! - \b SSI_ADV_MODE_READ_WRITE - The advanced mode of operation where data is
|
|
//! written to and read from the slave; this mode is the same as
|
|
//! \b SSI_ADV_MODE_LEGACY but allows transitions to Bi- or Quad-SPI
|
|
//! operation.
|
|
//! - \b SSI_ADV_MODE_BI_READ - The advanced mode of operation where data is
|
|
//! read from the slave in Bi-SPI mode, with two bits of data read on every
|
|
//! SSI clock.
|
|
//! - \b SSI_ADV_MODE_BI_WRITE - The advanced mode of operation where data is
|
|
//! written to the slave in Bi-SPI mode, with two bits of data written on
|
|
//! every SSI clock.
|
|
//! - \b SSI_ADV_MODE_QUAD_READ - The advanced mode of operation where data is
|
|
//! read from the slave in Quad-SPI mode, with four bits of data read on
|
|
//! every SSI clock.
|
|
//! - \b SSI_ADV_MODE_QUAD_WRITE - The advanced mode of operation where data is
|
|
//! written to the slave in Quad-SPI mode, with four bits of data written on
|
|
//! every SSI clock.
|
|
//!
|
|
//! The following mode transitions are valid (other transitions produce
|
|
//! undefined results):
|
|
//!
|
|
//! \verbatim
|
|
//! +----------+-------------------------------------------------------------+
|
|
//! |FROM | TO |
|
|
//! | |Legacy|Write|Read Write|Bi Read|Bi Write|Quad Read|Quad Write|
|
|
//! +----------+------+-----+----------+-------+--------+---------+----------+
|
|
//! |Legacy | yes | yes | yes | | | | |
|
|
//! |Write | yes | yes | yes | yes | yes | yes | yes |
|
|
//! |Read/Write| yes | yes | yes | yes | yes | yes | yes |
|
|
//! |Bi Read | | yes | yes | yes | yes | | |
|
|
//! |Bi write | | yes | yes | yes | yes | | |
|
|
//! |Quad read | | yes | yes | | | yes | yes |
|
|
//! |Quad write| | yes | yes | | | yes | yes |
|
|
//! +----------+------+-----+----------+-------+--------+---------+----------+
|
|
//! \endverbatim
|
|
//!
|
|
//! When using an advanced mode of operation, the SSI module must have been
|
|
//! configured for eight data bits and the \b SSI_FRF_MOTO_MODE_0 protocol.
|
|
//! The advanced mode operation that is selected applies only to data newly
|
|
//! written into the FIFO; the data that is already present in the FIFO is
|
|
//! handled using the advanced mode of operation in effect when that data was
|
|
//! written.
|
|
//!
|
|
//! Switching into and out of legacy mode should only occur when the FIFO is
|
|
//! empty.
|
|
//!
|
|
//! \note The availability of the advanced mode of SSI operation varies with
|
|
//! the Tiva part and SSI in use. Please consult the data sheet for the
|
|
//! part in use to determine whether this support is available.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIAdvModeSet(uint32_t ui32Base, uint32_t ui32Mode)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Mode == SSI_ADV_MODE_LEGACY) ||
|
|
(ui32Mode == SSI_ADV_MODE_WRITE) ||
|
|
(ui32Mode == SSI_ADV_MODE_READ_WRITE) ||
|
|
(ui32Mode == SSI_ADV_MODE_BI_READ) ||
|
|
(ui32Mode == SSI_ADV_MODE_BI_WRITE) ||
|
|
(ui32Mode == SSI_ADV_MODE_QUAD_READ) ||
|
|
(ui32Mode == SSI_ADV_MODE_QUAD_WRITE));
|
|
|
|
//
|
|
// Set the SSI mode of operation.
|
|
//
|
|
HWREG(ui32Base + SSI_O_CR1) =
|
|
((HWREG(ui32Base + SSI_O_CR1) & ~(SSI_CR1_DIR | SSI_CR1_MODE_M)) |
|
|
ui32Mode);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Puts a data element into the SSI transmit FIFO as the end of a frame.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param ui32Data is the data to be transmitted over the SSI interface.
|
|
//!
|
|
//! This function places the supplied data into the transmit FIFO of the
|
|
//! specified SSI module, marking it as the end of a frame. If there is no
|
|
//! space available in the transmit FIFO, this function waits until there is
|
|
//! space available before returning. After this byte is transmitted by the
|
|
//! SSI module, the FSS signal de-asserts for at least one SSI clock.
|
|
//!
|
|
//! \note The upper 24 bits of \e ui32Data are discarded by the hardware.
|
|
//!
|
|
//! \note The availability of the advanced mode of SSI operation varies with
|
|
//! the Tiva part and SSI in use. Please consult the data sheet for the
|
|
//! part in use to determine whether this support is available.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIAdvDataPutFrameEnd(uint32_t ui32Base, uint32_t ui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Data & 0xff) == 0);
|
|
|
|
//
|
|
// Wait until there is space.
|
|
//
|
|
while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF))
|
|
{
|
|
}
|
|
|
|
//
|
|
// Write the data to the SSI.
|
|
//
|
|
HWREG(ui32Base + SSI_O_CR1) |= SSI_CR1_EOM;
|
|
HWREG(ui32Base + SSI_O_DR) = ui32Data;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Puts a data element into the SSI transmit FIFO as the end of a frame.
|
|
//!
|
|
//! \param ui32Base specifies the SSI module base address.
|
|
//! \param ui32Data is the data to be transmitted over the SSI interface.
|
|
//!
|
|
//! This function places the supplied data into the transmit FIFO of the
|
|
//! specified SSI module, marking it as the end of a frame. After this byte is
|
|
//! transmitted by the SSI module, the FSS signal de-asserts for at least one
|
|
//! SSI clock. If there is no space in the FIFO, then this function returns a
|
|
//! zero.
|
|
//!
|
|
//! \note The upper 24 bits of \e ui32Data are discarded by the hardware.
|
|
//!
|
|
//! \note The availability of the advanced mode of SSI operation varies with
|
|
//! the Tiva part and SSI in use. Please consult the data sheet for the
|
|
//! part in use to determine whether this support is available.
|
|
//!
|
|
//! \return Returns the number of elements written to the SSI transmit FIFO.
|
|
//
|
|
//*****************************************************************************
|
|
int32_t
|
|
SSIAdvDataPutFrameEndNonBlocking(uint32_t ui32Base, uint32_t ui32Data)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
ASSERT((ui32Data & 0xff) == 0);
|
|
|
|
//
|
|
// Check for space to write.
|
|
//
|
|
if(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF)
|
|
{
|
|
HWREG(ui32Base + SSI_O_CR1) |= SSI_CR1_EOM;
|
|
HWREG(ui32Base + SSI_O_DR) = ui32Data;
|
|
return(1);
|
|
}
|
|
else
|
|
{
|
|
return(0);
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures the SSI advanced mode to hold the SSIFss signal during the full
|
|
//! transfer.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//!
|
|
//! This function configures the SSI module to de-assert the SSIFss signal
|
|
//! during the entire data transfer when using one of the advanced modes
|
|
//! (instead of briefly de-asserting it after every byte). When using this
|
|
//! mode, SSIFss can be directly controlled via SSIAdvDataPutFrameEnd() and
|
|
//! SSIAdvDataPutFrameEndNonBlocking().
|
|
//!
|
|
//! \note The availability of the advanced mode of SSI operation varies with
|
|
//! the Tiva part and SSI in use. Please consult the data sheet for the
|
|
//! part in use to determine whether this support is available.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIAdvFrameHoldEnable(uint32_t ui32Base)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Set the hold frame bit.
|
|
//
|
|
HWREG(ui32Base + SSI_O_CR1) |= SSI_CR1_FSSHLDFRM;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures the SSI advanced mode to de-assert the SSIFss signal after every
|
|
//! byte transfer.
|
|
//!
|
|
//! \param ui32Base is the base address of the SSI module.
|
|
//!
|
|
//! This function configures the SSI module to de-assert the SSIFss signal
|
|
//! for one SSI clock cycle after every byte is transferred using one of the
|
|
//! advanced modes (instead of leaving it asserted for the entire transfer).
|
|
//! This mode is the default operation.
|
|
//!
|
|
//! \note The availability of the advanced mode of SSI operation varies with
|
|
//! the Tiva part and SSI in use. Please consult the data sheet for the
|
|
//! part in use to determine whether this support is available.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
SSIAdvFrameHoldDisable(uint32_t ui32Base)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_SSIBaseValid(ui32Base));
|
|
|
|
//
|
|
// Clear the hold frame bit.
|
|
//
|
|
HWREG(ui32Base + SSI_O_CR1) &= ~(SSI_CR1_FSSHLDFRM);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
// Close the Doxygen group.
|
|
//! @}
|
|
//
|
|
//*****************************************************************************
|