void FLASH_ByteWrite (FLADDR addr, char byte)
{
   bit EA_SAVE = EA;                   // Preserve EA
   char xdata * data pwrite;           // FLASH write pointer

   EA = 0;                             // Disable interrupts

   VDM0CN = 0xA0;                      // Enable VDD monitor and high threshold

   RSTSRC = 0x02;                      // Enable VDD monitor as a reset source

   pwrite = (char xdata *) addr;

   FLKEY  = 0xA5;                      // Key Sequence 1
   FLKEY  = 0xF1;                      // Key Sequence 2
   PSCTL |= 0x01;                      // PSWE = 1 which enables writes

   VDM0CN = 0xA0;                      // Enable VDD monitor and high threshold

   RSTSRC = 0x02;                      // Enable VDD monitor as a reset source

   *pwrite = byte;                     // Write the byte

   PSCTL &= ~0x01;                     // PSWE = 0 which disable writes

   EA = EA_SAVE;                       // Restore interrupts
}