231 lines
8.5 KiB
C
231 lines
8.5 KiB
C
/**************************************************************************//**
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* @file
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* @brief SPI implementation of Board Control interface
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* This implementation use the USART2 SPI interface to control board
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* control registers. It works
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* @author Energy Micro AS
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* @version 1.6.0
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******************************************************************************
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* @section License
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* <b>(C) Copyright 2010 Energy Micro AS, http://www.energymicro.com</b>
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******************************************************************************
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*
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* This source code is the property of Energy Micro AS. The source and compiled
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* code may only be used on Energy Micro "EFM32" microcontrollers.
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*
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* This copyright notice may not be removed from the source code nor changed.
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*
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* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
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* obligation to support this Software. Energy Micro AS is providing the
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* Software "AS IS", with no express or implied warranties of any kind,
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* including, but not limited to, any implied warranties of merchantability
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* or fitness for any particular purpose or warranties against infringement
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* of any proprietary rights of a third party.
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*
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* Energy Micro AS will not be liable for any consequential, incidental, or
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* special damages, or any other relief, or for any claim by any third party,
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* arising from your use of this Software.
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*
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*****************************************************************************/
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#include <stdio.h>
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#include "efm32.h"
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#include "efm32_usart.h"
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#include "efm32_gpio.h"
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#include "efm32_cmu.h"
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#include "dvk.h"
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#include "dvk_bcregisters.h"
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/* USART used for SPI access */
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#define USART_USED USART2
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#define USART_CLK cmuClock_USART2
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/* GPIO pins used, please refer to DVK user guide. */
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#define PIN_SPIBUS_CONNECT 13
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#define PORT_SPIBUS_CONNECT gpioPortC
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#define PIN_SPI_TX 2
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#define PORT_SPI_TX gpioPortC
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#define PIN_SPI_RX 3
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#define PORT_SPI_RX gpioPortC
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#define PIN_SPI_CLK 4
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#define PORT_SPI_CLK gpioPortC
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#define PIN_SPI_CS 5
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#define PORT_SPI_CS gpioPortC
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static volatile uint16_t *lastAddr = NULL;
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/**************************************************************************//**
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* @brief Initializes SPI interface for access to FPGA registers
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* for board control
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*****************************************************************************/
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static void spiInit(void)
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{
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USART_InitSync_TypeDef init = USART_INITSYNC_DEFAULT;
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/* Enable module clocks */
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CMU_ClockEnable(cmuClock_GPIO, true);
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CMU_ClockEnable(cmuClock_HFPER, true);
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CMU_ClockEnable(USART_CLK, true);
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/* Configure SPI bus connect pins, DOUT set to 0 */
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GPIO_PinModeSet(PORT_SPIBUS_CONNECT, PIN_SPIBUS_CONNECT, gpioModePushPull, 0);
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/* Configure SPI pins */
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GPIO_PinModeSet(PORT_SPI_TX, PIN_SPI_TX, gpioModePushPull, 0);
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GPIO_PinModeSet(PORT_SPI_RX, PIN_SPI_RX, gpioModePushPull, 0);
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GPIO_PinModeSet(PORT_SPI_CLK, PIN_SPI_CLK, gpioModePushPull, 0);
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/* Keep CS high to not activate slave */
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GPIO_PinModeSet(PORT_SPI_CS, PIN_SPI_CS, gpioModePushPull, 1);
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/* Enable pins at default location */
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USART_USED->ROUTE = USART_ROUTE_TXPEN | USART_ROUTE_RXPEN | USART_ROUTE_CLKPEN;
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/* Reset USART just in case */
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USART_Reset(USART_USED);
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/* Configure to use SPI master with manual CS */
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/* For now, configure SPI for worst case 32MHz clock in order to work for all */
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/* configurations. */
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init.refFreq = 32000000;
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init.baudrate = 7000000;
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USART_InitSync(USART_USED, &init);
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}
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/**************************************************************************//**
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* @brief Disables GPIO pins and USART from FPGA register access
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*****************************************************************************/
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static void spiDisable(void)
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{
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USART_Reset(USART_USED);
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/* Route setup must be reset separately */
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USART_USED->ROUTE = _USART_ROUTE_RESETVALUE;
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/* Disable SPI pins */
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GPIO_PinModeSet(PORT_SPIBUS_CONNECT, PIN_SPIBUS_CONNECT, gpioModeDisabled, 0);
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GPIO_PinModeSet(PORT_SPI_TX, PIN_SPI_TX, gpioModeDisabled, 0);
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GPIO_PinModeSet(PORT_SPI_RX, PIN_SPI_RX, gpioModeDisabled, 0);
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GPIO_PinModeSet(PORT_SPI_CLK, PIN_SPI_CLK, gpioModeDisabled, 0);
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GPIO_PinModeSet(PORT_SPI_CS, PIN_SPI_CS, gpioModeDisabled, 0);
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/* Disable USART clock - we can't disable GPIO or HFPER as we don't know who else
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* might be using it */
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CMU_ClockEnable(USART_CLK, false);
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}
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/**************************************************************************//**
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* @brief Perform SPI Transfer
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*****************************************************************************/
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static uint16_t spiAccess(uint8_t spiaddr, uint8_t rw, uint16_t spidata)
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{
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uint16_t tmp;
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GPIO_PinOutClear(PORT_SPI_CS, PIN_SPI_CS);
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/* For every byte sent, one is received */
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/* Write SPI address */
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USART_Tx(USART_USED, (spiaddr & 0x3) | rw << 3);
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/* Just ignore data read back */
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USART_Rx(USART_USED);
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/* SPI data LSB */
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USART_Tx(USART_USED, spidata & 0xFF);
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tmp = (uint16_t)USART_Rx(USART_USED);
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/* SPI data MSB */
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USART_Tx(USART_USED, spidata >> 8);
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tmp |= (uint16_t)USART_Rx(USART_USED) << 8;
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GPIO_PinOutSet(PORT_SPI_CS, PIN_SPI_CS);
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return tmp;
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}
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/**************************************************************************//**
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* @brief Performs SPI write to FPGA register
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* @param spiadr Address of register
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* @param spidata Data to write
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*****************************************************************************/
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static void spiWrite(uint8_t spiadr, uint16_t spidata)
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{
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spiAccess(spiadr, 0, spidata);
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}
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/**************************************************************************//**
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* @brief Performs SPI read from FPGA register
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* @param spiadr Address of register
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* @param spidata Dummy data
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*****************************************************************************/
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static uint16_t spiRead(uint8_t spiadr, uint16_t spidata)
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{
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return spiAccess(spiadr, 1, spidata);
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}
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/**************************************************************************//**
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* @brief Initializes DVK register access
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*****************************************************************************/
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void DVK_SPI_init(void)
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{
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uint16_t spiMagic;
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spiInit();
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/* Read "board control Magic" register to verify SPI is up and running */
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/* if not FPGA is configured to be in EBI mode */
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spiMagic = DVK_SPI_readRegister(BC_MAGIC);
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if (spiMagic != BC_MAGIC_VALUE)
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{
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/* Development Kit is configured to use EBI mode, restart of kit required */
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/* to use SPI for configuration */
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spiDisable();
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while (1) ;
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}
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}
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/**************************************************************************//**
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* @brief Disable and free up resources used by SPI board control access
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*****************************************************************************/
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void DVK_SPI_disable(void)
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{
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spiDisable();
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}
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/**************************************************************************//**
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* @brief Perform read from DVK board control register
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* @param addr Address of register to read from
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*****************************************************************************/
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uint16_t DVK_SPI_readRegister(volatile uint16_t *addr)
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{
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uint16_t data;
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if (addr != lastAddr)
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{
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spiWrite(0x00, 0xFFFF & ((uint32_t) addr)); /*LSBs of address*/
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spiWrite(0x01, 0xFF & ((uint32_t) addr >> 16)); /*MSBs of address*/
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spiWrite(0x02, (0x0C000000 & (uint32_t) addr) >> 26); /*Chip select*/
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}
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/* Read twice */
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data = spiRead(0x03, 0);
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data = spiRead(0x03, 0);
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lastAddr = addr;
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return data;
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}
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/**************************************************************************//**
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* @brief Perform write to DVK board control register
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* @param addr Address of register to write to
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* @param data 16-bit to write into register
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*****************************************************************************/
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void DVK_SPI_writeRegister(volatile uint16_t *addr, uint16_t data)
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{
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if (addr != lastAddr)
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{
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spiWrite(0x00, 0xFFFF & ((uint32_t) addr)); /*LSBs of address*/
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spiWrite(0x01, 0xFF & ((uint32_t) addr >> 16)); /*MSBs of address*/
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spiWrite(0x02, (0x0C000000 & (uint32_t) addr) >> 26); /*Chip select*/
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}
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spiWrite(0x03, data); /*Data*/
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lastAddr = addr;
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}
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