Flashing becomes slower

[Wilson]

Hi

I am quite puzzled why the programming process for my 89C51RD2BN is suddenly taking longer than it use to. Occasionally, it will also set off the unable to communicate (transmit/receive) error message after a while.

My code size did not change much and I can't think of why it is slower as I have kept everything the same. It is especially harder to debug this problem as the error is not consistent.

Would appreciate any advice. Thank

[Andy Ayre]

It sounds like for some reason Flash Magic is having to retry ISP operations - perhaps because the baud rate has for some reason become borderline or the device is not responding correctly all the time. Some things to check:

1. Do you have glitches on VCC?

2. Is the signal at the XTAL pins consistant and glitch free?

3. Do you have decoupling caps across VCC - GND?

4. If you lower the baud rate does the error message stop appearing (obviously programming will be slower)?

5. Are you using the High Speed Communications option? If so try turning it off - does the error message stop appearing?

[Wilson]

Hi

I installed the lastest version of Flash Magic and everything is back to normal.

Unfortunately, I wasnt able to find out what the problem was. But I am glad everything is working fine now.

Thank you for the advice.

Regards
Wilson