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JTAG debugger not working with enabled LMEM cache on M4 Core(iMX7)

Question asked by Alexander May on Jan 29, 2017
Latest reply on Apr 19, 2018 by RY

Hi,

 

I'm trying to improve performance of M4 execution by enabling 32KB of cache on iMX7. The application runs out of OCRAM e.g. 0x900000-0x93FFFF memory, and can be improved very much, by enabling LMEM-PS and moving the code segments to OCRAM alias, e.g. 0x20200000-0x2023FFFF memory. (actually NXP-Freertos package uses OCRAM-alias by default).

Everything works great.

For instance: by having some task be done within 25µs without cache, will be done within 3,6µs with enabled cache.

 

The only issue, is that once LMEM cache is enabled, JTAG debugger is not responding anymore. No step, step-in, step-out function are working. This makes software development very hard.

With disabled LMEM-PS cache, everything works correct, even from OCRAM alias memory.

 

Is there a trick fixing the issue?

 

I'm using DS-5 5.26.2 and ULINKpro D hardware debugger.

 

thank you in advance,

Alexander.

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