PIC读写程序存储器

贴上代码，为什么调试的时候执行到READ之后就直接跳到主函数第一行，而不是继续往下执行READ后面的代码，一直这样循环，到底怎么回事啊。
#include "p24fj64ga006.h"
//#define UINT32 unsigned long
#define UINT16 unsigned int
#define UINT8  unsigned char
#define FLASH_ERASEPAGE 0x4042
#define FLASH_PROGLINE  0x4001
void FlashReadData(UINT16 FlashAddr,UINT8 *Dest,UINT8 DataNum)
{
TBLPAG = 0x00;
for(;DataNum>0;DataNum--)
{ asm("tblrdl.b [%1],%0":"=r"(*Dest):"r"(FlashAddr));
   Dest++;
   asm("tblrdh.b [%1],%0":"=r"(*Dest):"r"(FlashAddr));
   Dest++;
   FlashAddr += 2;
}
// return 0;
}
void FlashErasePage(UINT16 FlashAddr)
{
   UINT16 temp16;
   NVMCON = FLASH_ERASEPAGE;
   TBLPAG = 0x00;
   temp16 = FlashAddr;
   asm("tblwtl w0,[w0]");
   NVMKEY = 0x55;
   NVMKEY = 0xaa;
   _WR = 1;
   Nop();
   Nop();
}
void FlashWriteData(UINT16 FlashAddr,UINT8 *Dest,UINT8 DataNum)
{
  UINT16 temp16;
  NVMCON = FLASH_ERASEPAGE;
  TBLPAG = 0x00;
  temp16 = FlashAddr;
  asm("tblwtl w0,[w0]");
  NVMKEY = 0x55;
  NVMKEY = 0xaa;
  _WR = 1;
  Nop();
  Nop();
  NVMCON = FLASH_PROGLINE;
  TBLPAG = 0x00;
  for(;DataNum>0;DataNum--)
{
  asm("tblwtl.b %0,[%1]"::"r"(*Dest),"d"(FlashAddr));
  Dest++;
  asm("tblwth.b %0,[%1]"::"r"(*Dest),"d"(FlashAddr));
  Dest++;
  FlashAddr += 2;
}
NVMKEY = 0x55;
NVMKEY = 0xaa;
_WR = 1;
Nop();
Nop();
}
void main()
{
AD1PCFG=0XFFFF;
int a[1]={0xffff,0x55aa};
int b[1];

TRISB=0;
LATB=0XFFFF;
FlashReadData(0xAC00,b,4);
Nop();
    Nop();
FlashErasePage(0XAC00);
Nop();
    Nop();
FlashWriteData(0xAC00,a,4);
Nop();
    Nop();
FlashReadData(0xAC00,b,4);
while(1);
}