Setting readout protection blocks SW programming.

[jellybean10025]

Posted on January 13, 2010 at 13:59

Setting readout protection blocks SW programming.

[jellybean10025]

Posted on May 17, 2011 at 13:37

We have set readout protection in a computer, and now we want to reprogram it via SW. Even though we have set the Cortex target driver setup to Erase Full Chip, it will no longer allow us to write to the computer either with load or debug.

How do we reset this chip so that the read protection doesn't also block writing a new program?

[jellybean10025]

Posted on May 17, 2011 at 13:37

We are using a high density STM32 and Keil toolchain.

[chikos33]

Posted on May 17, 2011 at 13:37

Hi,

Erasing the full chip has absolutely no effect when Readout Protection is active. Have you accessed the option bytes (@ 0x1FFFF800)? Normally, if you have access to the option bytes, you will just need to write to this address (@ 0x1FFFF800) a dummy value (to enable readout protection) then 0x000000A5 to disable the readout protection and have full access to the flash. You can access the option bytes through bootloader (if you have access to the USART pins) or through the tool memory viewer if you have one. I use IAR, I don't know about Keil. One more thing, you need to reset the device after this operation in order to be effective, otherwise, the option bytes are not loaded. Does it answer your question ? Regards and best luck :) [ This message was edited by: chikos33 on 14-01-2010 11:38 ]