I am having trouble with P89C51RC2 Devices. I program them with Flash-ISP.
Here is my programming procedure.

1. I momentarily pull down the PSEN line until i powerup the board
2. Power-up the microcontroller based board.
3. Launch Flash-ISP and connect it.
4. Load hex file in to Flash-ISP buffer. and issue command to Erase, Program
and Verify.
Value of BSB =0x00(boot status byte) , BLJB = 0

The chip get programmed without any trouble through Serial port. but then it
does not executes my program. Seems the microcontroller remains in Boot
loader code. To test this i launched hyperterminal and issued character 'U'
and found that i was getting the 'U' as echo indicating that the uC was
still in bootloader program.

Can anyone suggest whats wrong with my scheme. Althout I am using AT89C51RD2
microcontrollers on the same board without any trouble. And I use
Atmel -Flip to program this atmel chip witout any trouble. Unfortunately I
have some immediate availabitly trouble with AT89c51RD2 devices. and I got
to use P89C51RC2 /RD2 devices which i already have in stock.

Any share your experiences with P89C51R/A/B/C/D devices related with
in-system programming

Best regards

Asim