MSPM0G3507: How to use MDIV of G3507

Ryuuichi machida

Part Number: MSPM0G3507
Other Parts Discussed in Thread: ENERGYTRACE,

Hi,

I would like to set CPUCLK to 1MHz.
According to technical reference manual, when user want to set less than 4MHz, it seems that we can use MDIV.
So, I set MDIV following caution of technical reference manual, I can see less than 4MHz signal but I see something strenge point. So could you please confirm about below ?

Q1 : When I set 2MHz setting, I could see following signal (observe this signal by enabling CLK_OUT function.)

Actually, frequency is 2MHz but duty ratio is strange (For clock, in my understanding, duty ratio should be 1:1.)
Is it expected result ?

Q2 :
When I set 1MHz setting, I could NOT see 1MHz signal. (same signal as 2MHz pattern.)
Is it expected result ?

Best Regards,

3 months ago

0 Zoey Wei 3 months ago

TI__Genius 15081 points

Hi,

Let me have a test from my side.

Regards,

Zoey

0 Ryuuichi machida 3 months ago in reply to Zoey Wei

Guru 13495 points

Hi Zoey-san,

Thank you for your reply.
If possible, could you please send your confirmation result(or progress) by wednesday of this week ?

Best Regards,

0 Zoey Wei 3 months ago in reply to Ryuuichi machida

TI__Genius 15081 points

Hi Ryuuichi machida ,

Sure, there was Chinese public holiday these days, will check as soon as possible.

Regards,

Zoey

0 Zoey Wei 3 months ago in reply to Zoey Wei

TI__Genius 15081 points

Hi Ryuuichi machida ,

I have checked from my side, same as the customer.

2M:

1M:

They're all expected. Internal MCU frequency dividers often produce a non-50% duty cycle. They don't affect the application.

0 Ryuuichi machida 3 months ago in reply to Zoey Wei

Guru 13495 points

Hi,

Thank you for your reply.
For my question "2", as I said, I did not see 1MHz signal.
Is the differeence between "2MHz setting" and "1MHz setting" just MDIV value ?
If possible, could you share your sample code ?

Best Regards,

0 Zoey Wei 3 months ago in reply to Ryuuichi machida

TI__Genius 15081 points

Hi Ryuuichi machida ,

No what I change is set MDIV to 4 based from "2MHz setting"

0 Ryuuichi machida 3 months ago in reply to Zoey Wei

Guru 13495 points

Hi,

>No what I change is set MDIV to 4 based from "2MHz setting"
So, is the difference only below ?

* "2MHz setting" : Set MDIV to 2

* "1MHz setting" : Set MDIV to 4

Best Regards,

0 Zoey Wei 3 months ago in reply to Ryuuichi machida

TI__Genius 15081 points

Yes, exactly.

0 Ryuuichi machida 3 months ago in reply to Zoey Wei

Guru 13495 points

Hi,

The reason why I could not confirm 1MHz was due to my setting issue.
I have following question about MDIV.

* When I check power consumption on LP-MSPM0G3507 with EnergyTrace++.
When I measure four cases cpuclk=32MHz, 4MHz, 2MHz and 1MHz.

I have expected result from 32MHz -> 4MHz (almost 1/8). However, I could not observe expected result case of 4MHz -> 2MHz and 2MHz -> 1MHz.
Here is result of energyTrace++

32MHz

4MHz

Minimum current of 4MHz case became approx 1/8 compared to 32MHz. This is expected result.

2MHz

1MHz

Actually, minimum current decreased, however ratio is too small.
Is it expected result ?

Best Regards,

0 Zoey Wei 3 months ago in reply to Ryuuichi machida

TI__Genius 15081 points

Hi,

1. Looks like the value of power consumption is not only for M0, is the system level?

2. The power cannot calculate based on the frequence ratio, since there is the other static current...

Regards,

Zoey

0 Ryuuichi machida 3 months ago in reply to Zoey Wei

Guru 13495 points

Hi,

In previous data, since I enabled "clkout", so I disabled this function.

Here are result which all functions are disabled and IOs are set to "output" with "low". (I set "sleep0" as low power mode.)

32MHz

4MHz

There are similar spec to datasheet.(IDD"Sleep")

2MHz

1MHz

As I said previous thread, actually power consumption is decreased steadily. But ratio is too small.
Again, is it expected result ?

Best Regards.