Inability to start execution of final programmed code

[Ashwin M. Dhekne]

Hello everybody!!

I am using Flashmagic ver 1.74

I am using P89C51RD2HBP. In order to program this chip i have built a temporary programmer PCB with RS232 interface. At power Up I am tying PSEN to ground to ensure entry into boot ROM. I have been able to program the chip properly. I conclude this - since after programming i have read back and verified the code burnt into the chip and that matches correctly, with the HEX file on the harddisk.

My problem is that when I remove this programmed chip and place it into the final end product - the code does not execute. The code is completely debugged and it runs perfectly when the end product is put onto the emulator. In the end product, EA is tied to +5V, PSEN is Floating.

Any suggestions to address this problem will be most welcome.

Regards

Ashwin M. Dhekne

[Ingo]

updating the Status Byte.
After programming the Flash, the status byte should be programmed
to zero in order to allow execution of the user

[Andy Ayre]

Hmmm...Flash Magic should do that automatically. Please let me know if that turns out to not be the case.