external_memory.c

#include "lpc22xx.h"

void external_memory_Config(void)

{

  // set extended memory D0-D16 CS,CS1,CS2,CS3 A0-A19

  PINSEL2 &= ~(0x00000020);

  PINSEL2 |= 0x00000010;

  // enable /WE,/CS1

  PINSEL2 |= 0x00000900;

  // enable /CS2,/CS3

  PINSEL2 |= 0x00014000;

  // enable A0,A1, A2-A19

  PINSEL2 |= 0x0d800000;

  // set up the external sram on CS1

  // 1 idle cycle

  BCFG1 &= ~(0x0000000f);

  // 3 wait states, 16 bit wide bus

  BCFG1 &= ~(0x000003e0);

  BCFG1 |= 0x00000460;

  // 3 wait states

  BCFG1 &= ~(0x0000f800);

  BCFG1 |= 0x00001800;

  // 16 bit bus

  BCFG1 &= ~(0x30000000);

  BCFG1 |= 0x10000000;

  // set up the external non volatile sram on CS2

  // 1 idle cycle

  BCFG2 &= ~(0x0000000f);

  // 3 wait states, 16 bit wide bus

  BCFG2 &= ~(0x000003e0);

  BCFG2 |= 0x00000460; // 3 wait states

  BCFG2 &= ~(0x0000f800);

  BCFG2 |= 0x00001800;

  // 16 bit bus

  BCFG2 &= ~(0x30000000);

  BCFG2 |= 0x10000000;

  // set up the lcd on CS3

  // maximum idle cycles

  BCFG3 |= 0x0000000f;

  // maximum wait cycles

  BCFG3 |= 0x000003e0;

  // maximum wait cycles

  BCFG3 |= 0x0000f800;

  // 8 bit bus

  BCFG3 &= ~(0x30000000);

}