eeprom.c

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/*
 * @brief EEPROM example
 * This example show how to use the EEPROM interface
 *
 * @note
 * Copyright(C) NXP Semiconductors, 2012
 * All rights reserved.
 *
 * @par
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * LPC products.  This software is supplied "AS IS" without any warranties of
 * any kind, and NXP Semiconductors and its licensor disclaim any and
 * all warranties, express or implied, including all implied warranties of
 * merchantability, fitness for a particular purpose and non-infringement of
 * intellectual property rights.  NXP Semiconductors assumes no responsibility
 * or liability for the use of the software, conveys no license or rights under any
 * patent, copyright, mask work right, or any other intellectual property rights in
 * or to any products. NXP Semiconductors reserves the right to make changes
 * in the software without notification. NXP Semiconductors also makes no
 * representation or warranty that such application will be suitable for the
 * specified use without further testing or modification.
 *
 * @par
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, under NXP Semiconductors' and its
 * licensor's relevant copyrights in the software, without fee, provided that it
 * is used in conjunction with NXP Semiconductors microcontrollers.  This
 * copyright, permission, and disclaimer notice must appear in all copies of
 * this code.
 */

#include "board.h"
#include "string.h"

/*****************************************************************************
 * Private types/enumerations/variables
 ****************************************************************************/

/* Page used for storage */
#define PAGE_ADDR       0x01/* Page number */

/* Tag for checking if a string already exists in EEPROM */
#define CHKTAG          "NxP"
#define CHKTAG_SIZE     3

/* ASCII ESC character code */
#define ESC_CHAR        27

/* Read/write buffer (32-bit aligned) */
uint32_t buffer[EEPROM_PAGE_SIZE / sizeof(uint32_t)];

/*****************************************************************************
 * Public types/enumerations/variables
 ****************************************************************************/

/* Show current string stored in UART */
static void ShowString(char *str) {
 int stSize;

 /* Is data tagged with check pattern? */
 if (strncmp(str, CHKTAG, CHKTAG_SIZE) == 0) {
  /* Get next byte, which is the string size in bytes */
  stSize = (uint32_t) str[3];
  if (stSize > 32) {
   stSize = 32;
  }

  /* Add terminator */
  str[4 + stSize] = '\0';

  /* Show string stored in EEPROM */
  DEBUGSTR("Stored string found in EEEPROM\r\n");
  DEBUGSTR("-->");
  DEBUGSTR((char *) &str[4]);
  DEBUGSTR("<--\r\n");
 }
 else {
  DEBUGSTR("No string stored in the EEPROM\r\n");
 }
}

/* Get a string to save from the UART */
static uint32_t MakeString(uint8_t *str)
{
 int index, byte;
 char strOut[2];

 /* Get a string up to 32 bytes to write into EEPROM */
 DEBUGSTR("\r\nEnter a string to write into EEPROM\r\n");
 DEBUGSTR("Up to 32 bytes in length, press ESC to accept\r\n");

 /* Setup header */
 strncpy((char *) str, CHKTAG, CHKTAG_SIZE);

 /* Read until escape, but cap at 32 characters */
 index = 0;
 strOut[1] = '\0';
 byte = DEBUGIN();
 while ((index < 32) && (byte != ESC_CHAR)) {
  if (byte != EOF) {
   strOut[0] = str[4 + index] = (uint8_t) byte;
   DEBUGSTR(strOut);
   index++;
  }

  byte = DEBUGIN();
 }

 str[3] = (uint8_t) index;

 return (uint32_t) index;
}

/*****************************************************************************
 * Private functions
 ****************************************************************************/

int main(void)
{
 uint32_t stSize;
 uint8_t *ptr = (uint8_t *) buffer;
 volatile int loop = 1; /* For debug message only */

 Board_Init();

 /* Init EEPROM */
 Chip_EEPROM_Init(LPC_EEPROM);

 /* Read all data from EEPROM page */
 Chip_EEPROM_Read(LPC_EEPROM, 0, PAGE_ADDR, ptr, EEPROM_RWSIZE_8BITS, EEPROM_PAGE_SIZE);

 /* Check and display string if it exists */
 ShowString((char *) ptr);

 /* Get a string to save */
 stSize = MakeString(ptr);

 /* Erase page */
 Chip_EEPROM_Erase(LPC_EEPROM, PAGE_ADDR);

 /* Write header + size + data to page */
 if (Chip_EEPROM_Write(LPC_EEPROM, 0, PAGE_ADDR, ptr, EEPROM_RWSIZE_8BITS, (4 + stSize)) == SUCCESS) {
  DEBUGSTR("EEPROM write passed\r\n");
  DEBUGSTR("Reading back string...\r\n");

  /* Read all data from EEPROM page */
  Chip_EEPROM_Read(LPC_EEPROM, 0, PAGE_ADDR, ptr, EEPROM_RWSIZE_8BITS, EEPROM_PAGE_SIZE);

  /* Check and display string if it exists */
  ShowString((char *) ptr);
 }
 else {
  DEBUGSTR("EEPROM write failed\r\n");
 }

 /* Wait forever */
 while (loop) {}

 return 0;
}