Resolved

CCS/TMDXIDK5718: Measuring processing time on A15

Intellectual 870 points

koji fukumoto

Replies: 8

Views: 220

Part Number: TMDXIDK5718

Tool/software: Code Composer Studio

I am creating a boot program for MPU (A15) using "TMDXIDK5718".
I want to measure the processing time of a function in a program.

I tried the following code, but the return value of the “clock” function was always “0xFFFFFFFF”.

clock_t start = clock();
func();
clock_t end = clock();

I think I should use the "Performance Monitor Count" register.
But I don't know what code to write.
Could you provide a sample code like the one above?

Thank you.

Intellectual 393215 points

Biser Gatchev-XID
- Nov 29, 2019 7:05 AM
Hi,

Your query has been assigned to a TI engineer. Please note that feedback may be delayed due to holidays in the USA.

Best Regards

Biser
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Genius 11900 points

Frank Livingston
- Dec 2, 2019 11:55 PM
In reply to Biser Gatchev-XID:
Hi,

For CSL (bare-metal), please see the following files:
- pdk_am57xx_1_0_16/packages/ti/csl/arch/a15/cp15.h : header
- pdk_am57xx_1_0_16/packages/ti/csl/arch/a15/V1/performance_unit.asm : asm source
These functions are provided for PMU: ARM_CCNT_Enable, ARM_CCNT_Reset, ARM_CCNT_Read. I think you would simply call ARM_CCNT_Read() before (start) and after (end) your function call.

Please see this thread for using A15 PMU as a time stamp provider in an RTOS-based application:

https://e2e.ti.com/support/processors/f/791/t/617492?DRA756-A15-example-of-timestamp-provider-in-core-clock-cycles

Regards,
Frank
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Intellectual 870 points

koji fukumoto
- Dec 3, 2019 8:56 AM
In reply to Frank Livingston:
Thank you for your reply.
The following code was able to get a value like processing time.
```
unsigned int start_time, end_time;
ARM_CCNT_Enable();
start_time = ARM_CCNT_Read();
func();
end_time = ARM_CCNT_Read();
```
start_time = 0

end_time = 18052
The result was obtained.

How can I convert this "18052" to milliseconds?

Thank you.
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Genius 11900 points

Frank Livingston
- Dec 3, 2019 4:39 PM
In reply to koji fukumoto:
Hi,

Please see the header in performance_unit.asm:

* The CCNT is divided by 64 (by setting Bit 3 of PMNC to 1)
* CCNT Read returns the clock value divided by 64 cycles.
* To get the actual CPU cycle multiple it with 64

You can confirm the PMU Cycle Counter is configured this way be inspecting the assembly code in performance_unit.asm. To understand the code, please refer to relevant ARM documentation, e.g.
- DDI0438I_cortex_a15_r4p0_trm.pdf: ARM Cortex-A15 MPCore Processor Reference Manual. See Section 11.3, PMU register summary.
- DDI0406C_C_arm_architecture_reference_manual.pdf: ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition. This will provide details concerning the PMCR, PMCNTENSET, and PMCCNTR regiters, as well as details concerning the assembly language instructions.
To get a time in msec.:
- Multiply PMCCNTR "delta" (end-start) value by 64 to obtain CPU cycle count
- Divide CPU cycle count by CPU clock speed. This is the wall-clock time in seconds.
- Convert sec. to msec. by multiplying by 1000.
Regards,
Frank
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Intellectual 870 points

koji fukumoto
- Dec 4, 2019 12:33 AM
In reply to Frank Livingston:
Hi,
Thank you for your reply.

The CPU clock of TMDXIDK5718 is 1.5GHz.
Is the following calculation method correct?
```
unsigned int start_time, end_time;
double procMS;

ARM_CCNT_Enable();
start_time = ARM_CCNT_Read();
func();
end_time = ARM_CCNT_Read();

procMS = (end_time - start_time) * 64.0 / 1610612736.0 * 1000.0;
```
Thank you.
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Genius 11900 points

Frank Livingston
- Dec 4, 2019 3:11 PM
In reply to koji fukumoto:

I would multiply by 1.5e6 rather than 1.5*1024^3.
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Intellectual 870 points

koji fukumoto
- Dec 5, 2019 12:53 AM
In reply to Frank Livingston:

Hi,
Thank you for your reply.

It is confirmation just in case.
Is it “1.5e6” instead of “1.5e9”?
(Is "1,500,000" instead of "1,500,000,000"?)
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question
Genius 11900 points

Frank Livingston
- Dec 5, 2019 1:42 AM
In reply to koji fukumoto:

Hi,

Yes, it should be 1.5e9 (Giga), not 1.5e6 (Mega).

Regards,
Frank
- Locked
- Cancel
Do you have another question?

We are glad that we were able to resolve this issue, and will now proceed to close this thread.

If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.

Ask a related question Ask a new question