89C51RC2HBD SECURITY ERASING PROBLEM...

[grutozoid]

I'm able to connect, program part but when I want to verify, impossible because security 2 is set, which is normal for me...
Normally I dont do "verify" as I use "erase block used by hex file" and I also use "set security bit 2" which renders further reading impossible.
But when I realized that nothing worked after reset, even  simple led toggle, I'd try to erase all flash to reset security bits to be able to "verify"...
When I try to "erase all Flash+security", flash seems to be erased but not security and I get a message after a while: "operation failed erasing device"

Scope on TX/RX shows normal attemps when erasing or programming.

I also could read signature (15 C2 89), security bits, etc...

Psen and reset are operating using DTR and RTS as specified, ALE, P2.6 and P2.7 are pulled-up by 10k...

I'm using FM Version 3.50.197
8051/XA Driver Version 2.31.196
ARM Driver Version 1.23.196

Any ideas?

My next step is to try with a brand new one but a QFP44 is very dull to replace...

Thank's

Louis

After chip change, it work's... but I will not secure device until last rev done... anyway forget about that!

[Andy Ayre]

I'm not sure why you can't erase the security bits. It's a single command sent to the device that erases all the flash and the security bits, so Flash Magic has limited control. If Flash Magic is not reporting any errors then the device must be accepting and processing the command.

Andy

[grutozoid]

Thank's Andy,

Maybe CPU became defective after my thousand retry's... or when I plugged-unplugged all probes. I have 12V too on board. May be I accidentally shorted 12 to 5V... anyway, it's working now.

Happy to see that Murphy moved (temporarily for shure...)  in an another lab...

Thank's again!

Louis.