MCF5445x running code from internal SRAM

M_H_ — Fri, 07 Mar 2008 19:01:45 GMT

Hi,

Has anyone been able to run code in the internal SRAM of the MCF5445x processor without enabling back-door access? If you have, how did you do it?

I can run code if the back-door is enabled but according to the device errata you shouldn't enable back-door and core access at the same time. When I only enable the back-door my code runs about 40% slower which I assume is because back-door access is slower than core access and my stack is in the SRAM. If I don't enable back-door access then the processor resets as soon as a function is called that sits in the SRAM. I can read and write data (and the stack) when only core access is enabled but can't run code.

Thanks.

Malcolm

Re: MCF5445x running code from internal SRAM

M_H_ — Tue, 15 Apr 2008 15:31:13 GMT

So far I've learnt that there is an error in the manual regarding the internal SRAM but I have not found out what the solution is.

I believe it is only possible to have either code or data in the SRAM but not both when connected directly to the core.

It's about time a new manual was released for this processor since there are so many errors in the existing one (Rev 2) or at the very least an updated list of errata.

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MCF5445x running code from internal SRAM

Re: MCF5445x running code from internal SRAM