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simulator CPU vs. execution cycles (is it because of the cash and memory stalls in C6x?

Started by ahma...@yahoo.com May 29, 2008
Hi every body
I compute the execution cycles and MIPs for my algorithm on C64x
simulator using its profiler. But as I saw the "total cycles" item was very more than "CPU execution cycles" item. My question is that the "total cycles" is important or "execution cycles"?
Is the numbers of cycles is so big if we use C55x or it is because of
C64x structure(its cash levels)?
My algorithm is MELPe based and so it contains very big arrays and then the cash structure of C6x may slow down it???????is it true?

Regards
Hi,

using DMA for data transfer may improve your cycle count.

HTH

Gustl

a...@yahoo.com schrieb:
> My algorithm is MELPe based and so it contains very big arrays and then
> the cash structure of C6x may slow down it???????is it true?
>
> Regards
No it is not proper to use dma because if you know there is not any huge or chunk data transferring in MELPe but the huge tables are used as look up tables.
Regards

Hi every body
>I compute the execution cycles and MIPs for my algorithm on C64x
> simulator using its profiler. But as I saw the "total cycles" item was very more than "CPU execution cycles" item. My question is that the "total cycles" is important or "execution cycles"?
> Is the numbers of cycles is so big if we use C55x or it is because of
> C64x structure(its cash levels)?
>My algorithm is MELPe based and so it contains very big arrays and then the cash structure of C6x may slow down it???????is it true?
>
>Regards
Ahmad-

> I compute the execution cycles and MIPs for my algorithm on C64x
> simulator using its profiler. But as I saw the "total cycles" item
> was very more than "CPU execution cycles" item.
> My question is that the "total cycles" is important or "execution cycles"?
> Is the numbers of cycles is so big if we use C55x or it is because of
> C64x structure(its cash levels)?
> My algorithm is MELPe based and so it contains very big arrays and then
> the cash structure of C6x may slow down
> it???????is it true?

Additional non-CPU cycles are due to external memory access, I/O (peripheral) access, DMA, etc.

Which 64x device are you simulating? A device such as 6415 has enough onchip memory to hold all MELPe program and
codebook tables, so you would not need external memory (SDRAM).

Did you just load the MELPe distribution fixed-point C code? If so that's intended for x86 and doesn't have efficient
organization and memory usage. What does the simulator show as your total memory requirement?

-Jeff