Main Menu
Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - RIZ074

#1
Hi...

I've been programming some P89C51RD2HBA with Flash Magic 3.33 without problems. However have noticed that after a while, I can't get them to go into ISP mode anymore. When PSEN is set low & P89C51RD2HBA is RESET, it would just continue to execute the previously programmed code. This does not happen after 1 try, but is after a number of successful ISP programming.

Have verified the following :
P2.6 is HIGH on RESET
P2.7 is HIGH on RESET
EA is kept HIGH
PSEN is LOW
ALE is floating (not connected) - but goes HIGH on RESET.

Is there a way to overcome this problem ?