program p89LPC920 using MCB900

[doru]

Hi,
I have recently bought a MCB900 (vers.4). I never used the ISP
programming until now.
I succeeded to program PLCC28 microcontrollers, by plugging the LPC
into PLCC28 socket.
I have tryed to program other LPCs with ISP capabilities (having 20
pins), in TSSOP or DIL case.
I removed the PLCC28 microcontroller from MCB900 board;
I connected the P89LPC932's ISP lines of the MCB900 board, through a 5
wires cable, to a P89LPC920 in TSSOP20 case, from an external board
(P89LPC920 was soldered on the board):
(VDD,GND,RESET,RXD,and TXD) from the P89LPC932 socket to
(VDD,GND,RESET,RXD,and TXD) from the P89LPC920 board..
I respected the jumpers' positions Run-off, RST-on on MCB900 board, but
I couldn't program with Flash Magic the microcontroller from this new
board.
Could anybody help me...?
Thank you very much!

Doru

[Je Gold]

How long are the wires?  Are they short as possible?

You may need a decoupling capacitors across VDD and GND on the LPC920 board.

Is the LPC920 in a product or just a target board with only the 5 wires?
(there may be other things interfering with RESET TxD and RxD).

If you have a oscilloscope  - monitor the VDD for noise and correct 3v3 voltage during programming.

Joe