spi_str91x.c

This is an Real-Time Library (RL-ARM) Flash File System file manipulation example.

/*----------------------------------------------------------------------------
 *      R T L  -  F l a s h   F i l e   S y s t e m
 *----------------------------------------------------------------------------
 *      Name:    SPI_STR91X.C 
 *      Purpose: Serial Peripheral Interface Driver for STR91x
 *      Rev.:    V3.12
 *----------------------------------------------------------------------------
 *      This code is part of the RealView Run-Time Library.
 *      Copyright (c) 2004-2007 KEIL - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include <File_Config.h>
#include <91x_lib.h>                    /* STR91x definitions               */

/* SSP_SR - bit definitions. */
#define TFE     0x01
#define TNF     0x02
#define RNE     0x04
#define RFF     0x08
#define BSY     0x10

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

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

void spi_init (void) {
   /* Initialize and enable the SSP Interface module. */
   U32 i;

   /* SCLK, MISO1, MOSI1 are SSP pins. */
   SCU->GPIOOUT[5] &= 0x00FF;
   SCU->GPIOOUT[5] |= 0x4A00;
   SCU->GPIOIN[5]  |= 0x40;
   /* NSS is GPIO, output set to high. */
   GPIO5->DR[0x80<<2] = 0x80;

   /* Enable SPI in Master Mode, CPOL=1, CPHA=1 (Clock low-active). */
   SSP0->CR0 = 0x00C7;
   SSP0->CR1 = 0x0002;
   SSP0->PR  = 0xFE;

   /* Send SPI Command with card not selected at 400 KBit. */
   for (i = 0; i < 16; i++) {
      spi_send (0xFF);
   }

   /* Enable SSP auto select. */
   SCU->GPIOOUT[5] &= 0x3FFF;
   SCU->GPIOOUT[5] |= 0x8000;
}


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

void spi_hi_speed (BOOL on) {
   /* Set a SPI clock speed to desired value. */

   if (on == __TRUE) {
      /* Max. 20 MBit used for Data Transfer. */
      SSP0->PR = 0x02;
   }
   else {
      /* Max. 400 kBit used in Card Initialization. */
      SSP0->PR = 0xFE;
   }
}


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

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

   /* Wait if TNF cleared, Tx FIFO is full. */
   while ((SSP0->SR & TNF) == 0);
   SSP0->DR = outb;
   /* Wait if RNE cleared, Rx FIFO is empty. */
   while ((SSP0->SR & RNE) == 0);
   inb = SSP0->DR;
   return (inb);
}


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