spi_lm3s37x8.c

keil arm flash fs 最新版 在Ｋｅｉｌ ａｒｍ下使用

/*----------------------------------------------------------------------------
 *      R T L  -  F l a s h   F i l e   S y s t e m
 *----------------------------------------------------------------------------
 *      Name:    SPI_LM3S37x8.C 
 *      Purpose: Serial Peripheral Interface Driver for Luminary LM3S37x8
 *      Rev.:    V3.22
 *----------------------------------------------------------------------------
 *      This code is part of the RealView Run-Time Library.
 *      Copyright (c) 2004-2008 KEIL - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include <File_Config.h>
#include <LM3Sxxxx.H>

#ifdef SSI1
   #define SSIx_PERI    SYSCTL_PERIPH_SSI1
   #define SSIx_BASE    SSI1_BASE
#else
   #define SSIx_PERI    SYSCTL_PERIPH_SSI0
   #define SSIx_BASE    SSI0_BASE
#endif

/* Peripheral definitions for EK-LM3S37x8 board */
#define SSI_PORT_PERI   SYSCTL_PERIPH_GPIOA
#define CS_PORT_PERI    SYSCTL_PERIPH_GPIOA
#define SSI_PORT        GPIO_PORTA_BASE
#define CS_PORT         GPIO_PORTA_BASE

#define SSI_CS          GPIO_PIN_3
#define SSI_CLK         GPIO_PIN_2
#define SSI_RX          GPIO_PIN_4
#define SSI_TX          GPIO_PIN_5
#define SSI_PINS        (SSI_TX | SSI_RX | SSI_CLK)


/*----------------------------------------------------------------------------
 *      SPI Driver Functions
 *----------------------------------------------------------------------------
 *  Required functions for SPI driver module:
 *   - void spi_init ()
 *   - void spi_ss (U32 ss)
 *   - U8   spi_send (U8 outb)
 *   - void spi_hi_speed (BOOL on)
 *---------------------------------------------------------------------------*/

/*--------------------------- spi_init --------------------------------------*/

void spi_init (void) {
   /* Initialize and enable the SSP Interface module. */

   /* Enable the SSI peripherals. */
   SysCtlPeripheralEnable(SSIx_PERI);
   SysCtlPeripheralEnable(SSI_PORT_PERI);
   SysCtlPeripheralEnable(CS_PORT_PERI);

   /* Configure the appropriate pins to be SSI instead of GPIO */
   GPIODirModeSet(SSI_PORT, SSI_PINS, GPIO_DIR_MODE_HW);
   GPIODirModeSet(CS_PORT,  SSI_CS,   GPIO_DIR_MODE_OUT);
   GPIOPadConfigSet(SSI_PORT, SSI_PINS, GPIO_STRENGTH_4MA, GPIO_PIN_TYPE_STD_WPU);
   GPIOPadConfigSet(CS_PORT,  SSI_CS,   GPIO_STRENGTH_4MA, GPIO_PIN_TYPE_STD_WPU);

   /* Deassert the SSIx chip select */
   GPIOPinWrite(CS_PORT, SSI_CS, SSI_CS);

   /* Configure the SSIx port */
   SSIConfig(SSIx_BASE, SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, 400000, 8);
   SSIEnable(SSIx_BASE);
}


/*--------------------------- spi_hi_speed ----------------------------------*/

void spi_hi_speed (BOOL on) {
   /* Set a SPI clock to low/high speed for SD/MMC. */
   U32 clk;

   if (on == __TRUE) {
      /* Max. 20 MBit used for Data Transfer. */
      clk = 12500000;                   /* Maximum allowed clock is 12.5MHz. */
   }
   else {
      /* Max. 400 kBit used in Card Initialization. */
      clk = 400000;
   }
   SSIDisable(SSIx_BASE);
   SSIConfig (SSIx_BASE, SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, clk, 8);
   SSIEnable (SSIx_BASE);
}


/*--------------------------- spi_ss ----------------------------------------*/

void spi_ss (U32 ss) {
   /* Enable/Disable SPI Chip Select */

   HWREG(CS_PORT + (GPIO_O_DATA + (SSI_CS << 2))) = ss ? SSI_CS : 0;
}


/*--------------------------- spi_send --------------------------------------*/

U8 spi_send (U8 outb) {
   /* Write and Read a byte on SPI interface. */

   while(!(HWREG(SSIx_BASE + SSI_O_SR) & SSI_SR_TNF));
   HWREG(SSI0_BASE + SSI_O_DR) = outb;

   while(!(HWREG(SSIx_BASE + SSI_O_SR) & SSI_SR_RNE));
   return (HWREG(SSIx_BASE + SSI_O_DR));
}


/*----------------------------------------------------------------------------
 * end of file
 *---------------------------------------------------------------------------*/