MSP430F5438A-EP: Faster Timer Clock

Fred Assadi

Part Number: MSP430F5438A-EP

My MCU core can run as fast as 25 MHz. However, I need finer (10 nS) time slices and want my timer (TB0) to be sourced from a faster clock (100 MHz). Can TB0CLK or INCLK inputs be faster than the DCO generated CPU clock?

over 5 years ago

0 Eddie LaCost over 5 years ago

TI__Mastermind 45135 points

Hello Fred,

Maximum MCLK on the device is 25MHz. The maximum frequency external oscillator is 32MHz. We do not have any MSP430 which can use a 100MHz clock source. MSP432 has 48MHz and 120MHz controllers.

https://www.ti.com/microcontrollers/simplelink-mcus/wired-mcus/products.html

0 Fred Assadi over 5 years ago in reply to Eddie LaCost

Intellectual 330 points

Hi Eddie,

Thanks for your prompt reply. I understand the device internal and external osc max ratings. My question was can the timer be sourced from a faster input (faster than the CPU)

-Fred

0 Chester Gillon over 5 years ago in reply to Fred Assadi

Guru 92251 points

Fred Assadi said:
My question was can the timer be sourced from a faster input (faster than the CPU)

The datasheet shows the maximum external timer clock frequency is 25 MHz:

0 Chester Gillon over 5 years ago in reply to Eddie LaCost

Guru 92251 points

Eddie LaCost said:
We do not have any MSP430 which can use a 100MHz clock source.

What about the MSP430 Timer_D Module in Hi-Resolution Mode, which should allow an internal clock frequency up to 256 MHz?

0 Fred Assadi over 5 years ago in reply to Chester Gillon

Intellectual 330 points

Hi Chester,

Thanks for your suggestion about the Hi-Resolution Timer D option. Very few chips seem to have that module in them, but I'm glad to have learned about their existence for future projects. Thanks again!

Eddie,

I was looking for any tips or tricks where you could get some speed adanvtage (like a 2X or 4x) for your timer source clock by making it count both rising & falling edges or some such option. But it seems like you are stating that 25 MHz is the maximum clock rate and nothing more can be done.

Take care,

Fred

0 zrno soli over 5 years ago in reply to Fred Assadi

Guru 34753 points

Fred Assadi said:

I was looking for any tips or tricks where you could get some speed adanvtage (like a 2X or 4x) for your timer source clock by making it count both rising & falling edges or some such option. But it seems like you are stating that 25 MHz is the maximum clock rate and nothing more can be done.

Check this topic ...

0 Fred Assadi over 5 years ago in reply to zrno soli

Intellectual 330 points

Thank you for the link Zrno. I read it. However, I am using the timer in the counter mode and not capture so I'm not counting anything. Rather I am outputting a waveform using TB0.x output. I can't see how your proposed solution could work to address my problem.

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MSP430F5438A-EP: Faster Timer Clock