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Question Regarding SRAM and Instruction Cache MPC5643L

Question asked by tektronix on Dec 13, 2013
Latest reply on Feb 21, 2014 by tektronix

I have a question regarding the MPC5643L architecture. I saw

the reference manuals and the e200z4 data sheet too but

could not find this information. There is very little information

regarding the SRAM.


I enabled both the core of MPC5643L with both core

accessing the SRAM in their particular area. According to the

architecture of the Chip the processor cores share the SRAM

bus and must see a performance degradation. This is perhaps

not the case, the time to read for example a certain number of

32-bit word is same as when only one core access the RAM

instead of two. This tells that there is something in between

that is taking care of it.

(Note: I am not running the code from the Flash, I am running

the code from SRAM directly. We are using TRK-USB-

MPC5643L processor).


My other question is regarding the Instruction Cache. I tried

enabling the instruction cache by writing 3 to spr register

1011. Then inorder to evaluate the performance of the cache i

called few instructions  in the code but I don't

see any difference in the timings with/without instruction

cache enabled/Disabled)

Note: (For this task also I directly download the code to the

SRAM and start executing it from there.)



If I am missing anything please let me know.