nes-proj/cpu/msp430/flash.c

/**
 * \file
 * Functions for reading and writing flash ROM.
 * \author Adam Dunkels <adam@sics.se>
 */

/* Copyright (c) 2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * $Id: flash.c,v 1.2 2007/11/17 10:28:04 adamdunkels Exp $
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include <msp430x14x.h>
#include <io.h>
#include <signal.h>

#include "dev/flash.h"
#include "dev/watchdog.h"

#define FLASH_TIMEOUT 30
#define FLASH_REQ_TIMEOUT 150

static unsigned short ie1, ie2;

/*---------------------------------------------------------------------------*/
void
flash_setup(void)
{

  /* Disable all interrupts. */

  /* Clear interrupt flag1. */
  IFG1 = 0;

  /* Stop watchdog. */
  watchdog_stop();
  
  /* DCO(SMCLK) is 2,4576MHz, /6 = 409600 Hz
     select SMCLK for flash timing, divider 5+1 */
  FCTL2 = 0xA5C5;              

  /* disable all interrupts to protect CPU
     during programming from system crash */
  _DINT();                   

  /* disable all NMI-Interrupt sources */
  ie1 = IE1;
  ie2 = IE2;
  IE1 = 0x00;                  
  IE2 = 0x00;
}
/*---------------------------------------------------------------------------*/
void
flash_done(void)
{
  /* Enable interrupts. */
  IE1 = ie1;
  IE2 = ie2;
  _EINT();
  watchdog_start();
}
/*---------------------------------------------------------------------------*/
void
flash_clear(unsigned short *ptr)
{
  FCTL3 = 0xA500;               /* Lock = 0 */
  while(FCTL3 & 0x0001) nop();  /* Wait for BUSY = 0, not needed
				   unless run from RAM */
  FCTL1 = 0xA502;               /* ERASE = 1 */
  *ptr  = 0;                    /* erase Flash segment */
  FCTL1 = 0xA500;               /* ERASE = 0 automatically done?! */
  FCTL3 = 0xA510;               /* Lock = 1 */
}
/*---------------------------------------------------------------------------*/
void
flash_write(unsigned short *ptr, unsigned short word)
{
  FCTL3 = 0xA500;              /* Lock = 0 */
  while(FCTL3 & 0x0001) nop(); /* Wait for BUSY = 0, not needed unless
				  run from RAM */
  FCTL1 = 0xA540;              /* WRT = 1 */
  *ptr  = word;                /* program Flash word */
  FCTL1 = 0xA500;              /* WRT = 0 */
  FCTL3 = 0xA510;              /* Lock = 1 */
}
/*---------------------------------------------------------------------------*/