176 lines
6.3 KiB
C
176 lines
6.3 KiB
C
//###########################################################################
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//
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// FILE: F2837xD_Spi.c
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//
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// TITLE: F2837xD SPI Initialization & Support Functions.
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//
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//###########################################################################
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// $TI Release: F2837xD Support Library v3.05.00.00 $
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// $Release Date: Tue Jun 26 03:15:23 CDT 2018 $
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// $Copyright:
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// Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
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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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//###########################################################################
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//
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// Included Files
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//
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#include "F2837xD_device.h"
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#include "F2837xD_Examples.h"
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//
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// Calculate BRR: 7-bit baud rate register value
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// SPI CLK freq = 500 kHz
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// LSPCLK freq = CPU freq / 4 (by default)
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// BRR = (LSPCLK freq / SPI CLK freq) - 1
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//
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#if CPU_FRQ_200MHZ
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#define SPI_BRR ((200E6 / 4) / 500E3) - 1
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#endif
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#if CPU_FRQ_150MHZ
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#define SPI_BRR ((150E6 / 4) / 500E3) - 1
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#endif
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#if CPU_FRQ_120MHZ
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#define SPI_BRR ((120E6 / 4) / 500E3) - 1
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#endif
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//
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// InitSPI - This function initializes the SPI to a known state
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//
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void InitSpi(void)
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{
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// Initialize SPI-A
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// Set reset low before configuration changes
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// Clock polarity (0 == rising, 1 == falling)
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// 16-bit character
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// Enable loop-back
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SpiaRegs.SPICCR.bit.SPISWRESET = 0;
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SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;
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SpiaRegs.SPICCR.bit.SPICHAR = (16-1);
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SpiaRegs.SPICCR.bit.SPILBK = 1;
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// Enable master (0 == slave, 1 == master)
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// Enable transmission (Talk)
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// Clock phase (0 == normal, 1 == delayed)
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// SPI interrupts are disabled
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SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;
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SpiaRegs.SPICTL.bit.TALK = 1;
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SpiaRegs.SPICTL.bit.CLK_PHASE = 0;
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SpiaRegs.SPICTL.bit.SPIINTENA = 0;
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// Set the baud rate
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SpiaRegs.SPIBRR.bit.SPI_BIT_RATE = SPI_BRR;
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// Set FREE bit
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// Halting on a breakpoint will not halt the SPI
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SpiaRegs.SPIPRI.bit.FREE = 1;
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// Release the SPI from reset
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SpiaRegs.SPICCR.bit.SPISWRESET = 1;
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}
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//
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// InitSpiGpio - This function initializes GPIO pins to function as SPI pins.
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// Each GPIO pin can be configured as a GPIO pin or up to 3
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// different peripheral functional pins. By default all pins come
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// up as GPIO inputs after reset.
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//
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// Caution:
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// For each SPI peripheral
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// Only one GPIO pin should be enabled for SPISOMO operation.
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// Only one GPIO pin should be enabled for SPISOMI operation.
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// Only one GPIO pin should be enabled for SPICLK operation.
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// Only one GPIO pin should be enabled for SPISTE operation.
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// Comment out other unwanted lines.
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//
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void InitSpiGpio()
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{
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InitSpiaGpio();
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}
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//
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// InitSpiaGpio - Initialize SPIA GPIOs
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//
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void InitSpiaGpio()
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{
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EALLOW;
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//
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// Enable internal pull-up for the selected pins
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//
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// Pull-ups can be enabled or disabled by the user.
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// This will enable the pullups for the specified pins.
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// Comment out other unwanted lines.
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//
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GpioCtrlRegs.GPAPUD.bit.GPIO16 = 0; // Enable pull-up on GPIO16 (SPISIMOA)
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// GpioCtrlRegs.GPAPUD.bit.GPIO5 = 0; // Enable pull-up on GPIO5 (SPISIMOA)
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GpioCtrlRegs.GPAPUD.bit.GPIO17 = 0; // Enable pull-up on GPIO17 (SPISOMIA)
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// GpioCtrlRegs.GPAPUD.bit.GPIO3 = 0; // Enable pull-up on GPIO3 (SPISOMIA)
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GpioCtrlRegs.GPAPUD.bit.GPIO18 = 0; // Enable pull-up on GPIO18 (SPICLKA)
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GpioCtrlRegs.GPAPUD.bit.GPIO19 = 0; // Enable pull-up on GPIO19 (SPISTEA)
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//
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// Set qualification for selected pins to asynch only
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//
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// This will select asynch (no qualification) for the selected pins.
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// Comment out other unwanted lines.
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//
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GpioCtrlRegs.GPAQSEL2.bit.GPIO16 = 3; // Asynch input GPIO16 (SPISIMOA)
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// GpioCtrlRegs.GPAQSEL1.bit.GPIO5 = 3; // Asynch input GPIO5 (SPISIMOA)
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GpioCtrlRegs.GPAQSEL2.bit.GPIO17 = 3; // Asynch input GPIO17 (SPISOMIA)
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// GpioCtrlRegs.GPAQSEL1.bit.GPIO3 = 3; // Asynch input GPIO3 (SPISOMIA)
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GpioCtrlRegs.GPAQSEL2.bit.GPIO18 = 3; // Asynch input GPIO18 (SPICLKA)
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GpioCtrlRegs.GPAQSEL2.bit.GPIO19 = 3; // Asynch input GPIO19 (SPISTEA)
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//
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//Configure SPI-A pins using GPIO regs
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//
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// This specifies which of the possible GPIO pins will be SPI functional
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// pins.
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// Comment out other unwanted lines.
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//
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GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 1; // Configure GPIO16 as SPISIMOA
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// GpioCtrlRegs.GPAMUX1.bit.GPIO5 = 2; // Configure GPIO5 as SPISIMOA
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GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 1; // Configure GPIO17 as SPISOMIA
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// GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 2; // Configure GPIO3 as SPISOMIA
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GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 1; // Configure GPIO18 as SPICLKA
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GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 1; // Configure GPIO19 as SPISTEA
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EDIS;
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}
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//
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// End of file
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//
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