void ReadSerialFlashPage(uint16 PageNum, uint8 *pBuffer)
{
  uint16 i;
 
  // Send command packet.
  SPIputchar(0xd2);                  // Main Memory Page Read command.
  SPIputchar((PageNum >> 7) & 0xff); // 0 0 0 0 PA10 PA9 PA8 PA7
  SPIputchar((PageNum << 1) & 0xff); // PA6 PA5 PA4 PA3 PA2 PA1 PA0 BA8(=0)
  SPIputchar(0x00);                  // BA7..BA0 = 0x00
  SPIputchar(0x00);   // Don't care.
  SPIputchar(0x00);   // Don't care.
  SPIputchar(0x00);   // Don't care.
  SPIputchar(0x00);   // Don't care.
 
  // Copy returned data from flash to RAM.
  for (i = 0; i < 256; i++)
    *pBuffer++ = SPIgetchar();   
}