LP-AM243: Questions for GTC(Global Timebase Counter)

Koichiro Tashiro

Part Number: LP-AM243

Hi,

My customer is evaluating LP-AM243 and found below two questions.
Could you answer them?

Q1) How to clear GTC counter value.
According to TRM (SPRUIM2E), Table 12-5294 and Table 12-5297 description.
The counter value can be cleared to zero by writing zero to these register while the counter is disabled (GTC0_GTC_CFG1.EN=0).
The customer tried it, but it does not work. The counter value was unchanged.
Could you tell me how to clear the counter?

Q2) GTC0_GTC_CFG3 physical address
It seems address mismatch in Table 12-5314. GTC0_GTC_CFG3 Registers.
If base address is 00AB 0000h, physical address for GTC0_GTC_CFG3 should be 00AB 0008h.
Which one is correct?

Thanks and regards,
Koichiro Tashiro

over 3 years ago

0 Ming Wei over 3 years ago

TI__Guru 56205 points

Hi Koihiro-san,

The GTC_CNTCV_LO seems cannot be changed even the system counter is disabled, but the GTC_CNTCV_HI can be cleared when system counter is disabled.

I will report this to the IP team.

Best regards,

Ming

0 Ming Wei over 3 years ago in reply to Ming Wei

TI__Guru 56205 points

Hi Koihiro-san,

Q1) The order of clearing is important. Please clear the GTC_CNTCV_LO first than the GTC_CNTCV_HI. This way the GTC_CNTCV_HI will be cleared, but GTC_CNTCV_LO will continue to count.

There is a workaround to this issue: only clear the GTC_CNTCV_HI when the GTC_CNTCV_LO is 0.

Q2) Yes. You are correct. It is a typo. It should be 00AB 0008h

Best regards,

Ming

0 Koichiro Tashiro over 3 years ago in reply to Ming Wei

TI__Mastermind 22945 points

Hi Ming,

Thanks for your reply and Q2 is closed.
For Q1, the customer tried below two tests on EVM, but both did not work. Counters were not cleared to zero.

test-a) Clear only GTC_CNTCV_HI.
test-b) Clear GTC_CNTCV_LO first, then clear GTC_CNTCV_HI.

Thanks and regards,
Koichiro Tashiro

+1 Ming Wei over 3 years ago in reply to Koichiro Tashiro

TI__Guru 56205 points

Hi Koichiro-san,

Did they do the following:

1. disable the GTC

2. Clear GTC_CNTCV_LO first, then clear GTC_CNTCV_HI.

3. enable the GTC. Once the GTC is enabled, the GTC_CNTCV_HI will be cleared.

Best regards,

Ming

0 Koichiro Tashiro over 3 years ago in reply to Ming Wei

TI__Mastermind 22945 points

Hi Ming,

Thanks! The step#3 was missing.
The customer confirmed the counter was cleared with step#3.

Thanks and regards,
Koichiro Tashiro

0 Fleenor over 3 years ago in reply to Koichiro Tashiro

TI__Mastermind 25093 points

Hi Koichiro-san,

We wanted to inform you that two internal tickets have been filed to resolve these issues in the TRM and track to closure.

SITARAAPPS-3340: Fix GTC0_GTC_CFG3 Physical Address

SITARAAPPS-3341: Clarify necessary steps to clear the GTC_CNTCV_HI value to zero in chapter content.

We will close this ticket now, please feel free to create another if any further issues arise.

Best Regards,

Zackary Fleenor

0 Koichiro Tashiro over 2 years ago in reply to Fleenor

TI__Mastermind 22945 points

Hi Zackary,

Thanks for taking actions!

Thanks and regards,
Koichiro Tashiro

Arm-based microcontrollers

Arm-based microcontrollers forum

LP-AM243: Questions for GTC(Global Timebase Counter)