Execute-Only-Memory

lwang · ‎2004-06-03

Posted on June 03, 2004 at 13:39

Execute-Only-Memory

lwang · ‎2011-05-17

Posted on May 17, 2011 at 12:01

I am using uPSD33xx. I would like to make one of the Secondary Flash Sector ''execute-only''. That is, I want Code in other Sectors be able to CALL or JUMP to Code in this Sector but unable to use MOVC to read contains of this Sector.

Can I use the CPLD to accomplish this? Where can I find more information about the CPLD in uPSD33xx? The datasheet does not seem to provide enough information about the details of the Macrocells.

jdaniel · ‎2011-05-17

Posted on May 17, 2011 at 12:01

Lichen,

I think you're going to be out of luck on that one. Unfortunately, all methods in the 8032 core that access ''code memory'' utilize the PSEN signal and from a hardware perspective, there's no easy way to distinguish between a code fetch for execution and a fetch from a MOVC.

Best Regards,

Phaze426