//*****************************************************************************
//
// soft_spi_master.c - Example demonstrating how to configure SoftSSI.
//
// Copyright (c) 2010-2011 Texas Instruments Incorporated. All rights reserved.
// Software License Agreement
//
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
//
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 7243 of the Stellaris Firmware Development Package.
//
//*****************************************************************************
#include <string.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "utils/softssi.h"
#include "utils/uartstdio.h"
//*****************************************************************************
//
//! \addtogroup ssi_examples_list
//! <h1>SoftSSI Master (soft_spi_master)</h1>
//!
//! This example shows how to configure the SoftSSI module. The code will send
//! three characters on the master Tx then polls the receive FIFO until 3
//! characters are received on the master Rx.
//!
//! This example uses the following peripherals and I/O signals. You must
//! review these and change as needed for your own board:
//! - GPIO Port A peripheral (for SoftSSI pins)
//! - SoftSSICLK - PA2
//! - SoftSSIFss - PA3
//! - SoftSSIRx - PA4
//! - SoftSSITx - PA5
//!
//! The following UART signals are configured only for displaying console
//! messages for this example. These are not required for operation of
//! SoftSSI.
//! - UART0 peripheral
//! - GPIO Port A peripheral (for UART0 pins)
//! - UART0RX - PA0
//! - UART0TX - PA1
//!
//! This example uses the following interrupt handlers. To use this example
//! in your own application you must add these interrupt handlers to your
//! vector table.
//! - SysTickIntHandler
//!
//! \note This example provide the same functionality using the same pins as
//! the spi_master example. As such, it can be used as a guide for how to
//! convert code which uses hardware SSI to the SoftSSI module.
//
//*****************************************************************************
//*****************************************************************************
//
// Number of bytes to send and receive.
//
//*****************************************************************************
#define NUM_SSI_DATA 3
//*****************************************************************************
//
// The persistent state of the SoftSSI peripheral.
//
//*****************************************************************************
tSoftSSI g_sSoftSSI;
//*****************************************************************************
//
// The data buffer that is used as the transmit FIFO. The size of this buffer
// can be increased or decreased as required to match the transmit buffering
// requirements of your application.
//
//*****************************************************************************
unsigned short g_pusTxBuffer[16];
//*****************************************************************************
//
// The data buffer that is used as the receive FIFO. The size of this buffer
// can be increased or decreased as required to match the receive buffering
// requirements of your application.
//
//*****************************************************************************
unsigned short g_pusRxBuffer[16];
//*****************************************************************************
//
// This function sets up UART0 to be used for a console to display information
// as the example is running.
//
//*****************************************************************************
void
InitConsole(void)
{
//
// Enable GPIO port A which is used for UART0 pins.
// TODO: change this to whichever GPIO port you are using.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
//
// Configure the pin muxing for UART0 functions on port A0 and A1.
// This step is not necessary if your part does not support pin muxing.
// TODO: change this to select the port/pin you are using.
//
GPIOPinConfigure(GPIO_PA0_U0RX);
GPIOPinConfigure(GPIO_PA1_U0TX);
//
// Select the alternate (UART) function for these pins.
// TODO: change this to select the port/pin you are using.
//
GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
//
// Initialize the UART for console I/O.
//
UARTStdioInit(0);
}
//*****************************************************************************
//
// The interrupt handler for the SysTick interrupt.
//
//*****************************************************************************
void
SysTickIntHandler(void)
{
//
// Call the SoftSSI timer tick.
//
SoftSSITimerTick(&g_sSoftSSI);
}
//*****************************************************************************
//
// Configure SoftSSI in SPI mode 0. This example will send out 3 bytes of
// data, then wait for 3 bytes of data to come in. This will all be done using
// the polling method.
//
//*****************************************************************************
int
main(void)
{
unsigned long ulDataTx[NUM_SSI_DATA];
unsigned long ulDataRx[NUM_SSI_DATA];
unsigned long ulindex;
//
// Set the clocking to run directly from the external crystal/oscillator.
// TODO: The SYSCTL_XTAL_ value must be changed to match the value of the
// crystal on your board.
//
SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_16MHZ);
//
// Set up the serial console to use for displaying messages. This is
// just for this example program and is not needed for SSI operation.
//
InitConsole();
//
// Display the setup on the console.
//
UARTprintf("SoftSSI ->\n");
UARTprintf(" Data: 8-bit\n\n");
//
// For this example SoftSSI is used with PortA[5:2]. The actual port and
// pins used may be different on your design based on the set of GPIO pins
// available. GPIO port A needs to be enabled so these pins can be used.
// TODO: change this to whichever GPIO port you are using.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
//
// Configure the SoftSSI module. The size of the FIFO buffers can be
// changed to accommodate the requirements of your application. The GPIO
// pins utilized can also be changed.
// The pins are assigned as follows:
// PA2 - SoftSSICLK
// PA3 - SoftSSIFss
// PA4 - SoftSSIRx
// PA5 - SoftSSITx
// TODO: change this to select the port/pin you are using.
// TODO: change the buffer sizes to match your requirements.
//
memset(&g_sSoftSSI, 0, sizeof(g_sSoftSSI));
SoftSSIClkGPIOSet(&g_sSoftSSI, GPIO_PORTA_BASE, GPIO_PIN_2);
SoftSSIFssGPIOSet(&g_sSoftSSI, GPIO_PORTA_BASE, GPIO_PIN_3);
SoftSSIRxGPIOSet(&g_sSoftSSI, GPIO_PORTA_BASE, GPIO_PIN_4);
SoftSSITxGPIOSet(&g_sSoftSSI, GPIO_PORTA_BASE, GPIO_PIN_5);
SoftSSIRxBufferSet(&g_sSoftSSI, g_pusRxBuffer,
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