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//###########################################################################
//
// FILE: F2837xD_Spi.c
//
// TITLE: F2837xD SPI Initialization & Support Functions.
//
//###########################################################################
// $TI Release: F2837xD Support Library v3.05.00.00 $
// $Release Date: Tue Jun 26 03:15:23 CDT 2018 $
// $Copyright:
// Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the
// distribution.
//
// Neither the name of Texas Instruments Incorporated nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//###########################################################################
//
// Included Files
//
#include "F2837xD_device.h"
#include "F2837xD_Examples.h"
//
// Calculate BRR: 7-bit baud rate register value
// SPI CLK freq = 500 kHz
// LSPCLK freq = CPU freq / 4 (by default)
// BRR = (LSPCLK freq / SPI CLK freq) - 1
//
#if CPU_FRQ_200MHZ
#define SPI_BRR ((200E6 / 4) / 500E3) - 1
#endif
#if CPU_FRQ_150MHZ
#define SPI_BRR ((150E6 / 4) / 500E3) - 1
#endif
#if CPU_FRQ_120MHZ
#define SPI_BRR ((120E6 / 4) / 500E3) - 1
#endif
//
// InitSPI - This function initializes the SPI to a known state
//
void InitSpi(void)
{
// Initialize SPI-A
// Set reset low before configuration changes
// Clock polarity (0 == rising, 1 == falling)
// 16-bit character
// Enable loop-back
SpiaRegs.SPICCR.bit.SPISWRESET = 0;
SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;
SpiaRegs.SPICCR.bit.SPICHAR = (16-1);
SpiaRegs.SPICCR.bit.SPILBK = 1;
// Enable master (0 == slave, 1 == master)
// Enable transmission (Talk)
// Clock phase (0 == normal, 1 == delayed)
// SPI interrupts are disabled
SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;
SpiaRegs.SPICTL.bit.TALK = 1;
SpiaRegs.SPICTL.bit.CLK_PHASE = 0;
SpiaRegs.SPICTL.bit.SPIINTENA = 0;
// Set the baud rate
SpiaRegs.SPIBRR.bit.SPI_BIT_RATE = SPI_BRR;
// Set FREE bit
// Halting on a breakpoint will not halt the SPI
SpiaRegs.SPIPRI.bit.FREE = 1;
// Release the SPI from reset
SpiaRegs.SPICCR.bit.SPISWRESET = 1;
}
//
// InitSpiGpio - This function initializes GPIO pins to function as SPI pins.
// Each GPIO pin can be configured as a GPIO pin or up to 3
// different peripheral functional pins. By default all pins come
// up as GPIO inputs after reset.
//
// Caution:
// For each SPI peripheral
// Only one GPIO pin should be enabled for SPISOMO operation.
// Only one GPIO pin should be enabled for SPISOMI operation.
// Only one GPIO pin should be enabled for SPICLK operation.
// Only one GPIO pin should be enabled for SPISTE operation.
// Comment out other unwanted lines.
//
void InitSpiGpio()
{
InitSpiaGpio();
}
//
// InitSpiaGpio - Initialize SPIA GPIOs
//
void InitSpiaGpio()
{
EALLOW;
//
// Enable internal pull-up for the selected pins
//
// Pull-ups can be enabled or disabled by the user.
// This will enable the pullups for the specified pins.
// Comment out other unwanted lines.
//
GpioCtrlRegs.GPAPUD.bit.GPIO16 = 0; // Enable pull-up on GPIO16 (SPISIMOA)
// GpioCtrlRegs.GPAPUD.bit.GPIO5 = 0; // Enable pull-up on GPIO5 (SPISIMOA)
GpioCtrlRegs.GPAPUD.bit.GPIO17 = 0; // Enable pull-up on GPIO17 (SPISOMIA)
// GpioCtrlRegs.GPAPUD.bit.GPIO3 = 0; // Enable pull-up on GPIO3 (SPISOMIA)
GpioCtrlRegs.GPAPUD.bit.GPIO18 = 0; // Enable pull-up on GPIO18 (SPICLKA)
GpioCtrlRegs.GPAPUD.bit.GPIO19 = 0; // Enable pull-up on GPIO19 (SPISTEA)
//
// Set qualification for selected pins to asynch only
//
// This will select asynch (no qualification) for the selected pins.
// Comment out other unwanted lines.
//
GpioCtrlRegs.GPAQSEL2.bit.GPIO16 = 3; // Asynch input GPIO16 (SPISIMOA)
// GpioCtrlRegs.GPAQSEL1.bit.GPIO5 = 3; // Asynch input GPIO5 (SPISIMOA)
GpioCtrlRegs.GPAQSEL2.bit.GPIO17 = 3; // Asynch input GPIO17 (SPISOMIA)
// GpioCtrlRegs.GPAQSEL1.bit.GPIO3 = 3; // Asynch input GPIO3 (SPISOMIA)
GpioCtrlRegs.GPAQSEL2.bit.GPIO18 = 3; // Asynch input GPIO18 (SPICLKA)
GpioCtrlRegs.GPAQSEL2.bit.GPIO19 = 3; // Asynch input GPIO19 (SPISTEA)
//
//Configure SPI-A pins using GPIO regs
//
// This specifies which of the possible GPIO pins will be SPI functional
// pins.
// Comment out other unwanted lines.
//
GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 1; // Configure GPIO16 as SPISIMOA
// GpioCtrlRegs.GPAMUX1.bit.GPIO5 = 2; // Configure GPIO5 as SPISIMOA
GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 1; // Configure GPIO17 as SPISOMIA
// GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 2; // Configure GPIO3 as SPISOMIA
GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 1; // Configure GPIO18 as SPICLKA
GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 1; // Configure GPIO19 as SPISTEA
EDIS;
}
//
// End of file
//
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