Help! About TSCH and TSCL of C6678?

Joe Quinby

Hello,I'm using TSCH and TSCL to delay the 5 billion cycles,there will be an error about 1 billion cycles,should be the first to read TSCL,then read TSCH carry occurs when abnormal. Will TSCH and TSCL address is the number? Continuous address it? It can be read simultaneously using these two do? Or there are other solutions?

over 9 years ago

0 Joe Quinby over 9 years ago

Prodigy 190 points

Pleaded guidance of senior engineer！please！

0 Shankari G over 9 years ago

TI__Mastermind 43955 points

Hi Joe Quinby,
Can you please refer to the below e2e post ?
e2e.ti.com/.../130875

Also refer to this wiki page.
processors.wiki.ti.com/.../Customizing_the_clock_and_time_Functions

0 Raja over 9 years ago

TI__Guru* 81335 points

Hi Joe Quinby,

As per my understanding, you can use TSCH & TSCL registers for profiling the code. You can use "NOP" instructions for delay loop.

Please refer the c66xx cpu instruction set reference guide(SPRUGH7) for information.

Thank you.

0 ran35366 over 9 years ago in reply to Raja

TI__Genius 12805 points

OK. I am not sure if I understand your question, but I will try to answer anyhow.

I enclosed a zip with four/cfs-file/__key/communityserver-discussions-components-files/791/7608.delayRoutine.zip files to this posting -

The first is a document. I was asked by a customer to show that the core indeed runs in 1G, and what is the accuracy of the clock. I answered by developing a program that shows the correct clock. The description of the code is in the attached word document.

Then I attach test code - this will show how to use the TSCL and TSCH to measure cycles. The third file is an assembly code that takes exact number of cycles, so we can relate number of cycles to time.

I attach a linker command file should you try and build the project that I used as well

I hope it helps. If I answer your question please close the thread

Ran

0 RobbySun over 9 years ago in reply to ran35366

Expert 1120 points

Thanks for your example code, Ran.

You said that the function consume N+31 cycles. Can you please explain how the extra 31 cycles are generated?

Thanks,

Robby

0 ran35366 over 9 years ago in reply to RobbySun

TI__Genius 12805 points

I assume this is the overhead of calling the function or some other overhead. (I developed it a long time ago)
You noticed that the overhead that is associated with calling the TSCL/TSCH is calculated in the main function and can be subtract from the measurements

Ran

0 RobbySun over 9 years ago in reply to ran35366

Expert 1120 points

Correct me if I am wrong, but I remember that, on C66x, jumping into the sub-function is 6 cycles, and returning from the sub-function is also 6 cycles. So the function call/return overhead would be 12 cycles. That's why I was wondering why there are 31 cycles overhead.
-Robby

0 Joe Quinby over 9 years ago in reply to ran35366

Prodigy 190 points

thank you for your answer,been busy recently,So there is no time to respond to your reply, I will continue to follow-up test.

0 Joe Quinby over 9 years ago in reply to Raja

Prodigy 190 points

Thank you for your answer,been busy recently,So there is no time to respond to your reply, thanks very much.

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Help! About TSCH and TSCL of C6678?