Starterware/AM4379: DMTimer 1ms accuracy

Hi,

What is the clock source? 32kHz or 32.768kHz?

Hi,

My customer is using CLK_32kHz.

Best regards,

Sasaki

This is the PER PLL generated 32.768kHz clock. Where exactly in the TRM did you see these settings? I cannot find them.

I saw this on page 2787 of TRM(spruhl7g).

"I made 1msec with the following setting of DMTimer1 described in TRM.

Input clock = 32KHz clock:
TPIR = 0x38A40
TNIR = 0xFFF44800
TLDR = 0xFFFFFFE0"

I don't see anything like this on p.2787

Thank you for your reply.

Biser Gatchev-XID said:

"I made 1msec with the following setting of DMTimer1 described in TRM.

Input clock = 32KHz clock:

Is the input clock above CLK_RC32K or CLK_32KHZ or CLK_M_OSC or CLK_32K_RTC?

Best regards,

Sasaki

See e2e.ti.com/.../2337370

I am asking how did you calculate these settings:

TPIR = 0x38A40
TNIR = 0xFFF44800
TLDR = 0xFFFFFFE0

I saw P2791.

For 1 ms tick with a 32768-Hz clock:
TPIR = 232000 → 0x38A40
TNIR = -768000 → 0xFFF44800
TLDR = 0xFFFFFFE0

But I did not know what to do with the clock source.

Best regards,
Sasaki

Hi,

Can you attach a project of made 1msec?

Best regards,
Sasaki

I have asked the factory team to comment on this. They will respond here.

Hi Biser-san,

Thank you for your support.

I will attach the program I created.
When DMTIMER_1MS_TPIR and DMTIMER_1MS_TNIR of this program are set to 0, an accurate 1 msec is output.
However, setting this to the following value will degrade accuracy.

*(volatile unsigned int *)DMTIMER_1MS_TPIR = 0x00038A40; //232000;
*(volatile unsigned int *)DMTIMER_1MS_TNIR = 0xFFF44800; //-768000;

Best regards,

SasakiTimer1_1msec.zip

Sasaki, how are you measuring the accuracy?

James