66AK2H DSP frequency change

Yara Gowayed

Other Parts Discussed in Thread: 66AK2H12

I am currently working on a Keystone 2 board and I am interested in changing the frequency of the DSP but each time I attempt to change it using the PLLM and output divider following the instruction in the sprugv2g.pdf file it fails. By failing I mean the board either stalls and never end the execution that it requires reset. I guess this happens because changing the frequency through MAINPLLCTL registers actually change the frequency of other peripherals like uart that used during booting.

I am new to this so I have some questions

1) since in 66AK2H12 PLLDIV1 is not programmable so the only values affecting this frequency change is the multiplier and output divider? ( I am suspecting that maybe another value is affecting it so the final frequency is out of range of allowed frequencies)

2)is there any other way to change the frequency of the DSP without having to change other frequencies of other peripherals?

**if anyone have other suggestions to try please let me know

Thanks,

Yara

over 9 years ago

0 Raja over 9 years ago

TI__Guru* 81335 points

Welcome to the TI E2E forum. I hope you will find many good answers here and in the TI.com documents and in the TI Wiki Pages (for processor issues). Be sure to search those for helpful information and to browse for the questions others may have asked on similar topics (e2e.ti.com). Please read all the links below my signature.

Are you working on EVM or Custom board? Please refer below wiki section to change the core clock.

Thank you.

Note: We strongly recommend you to create new e2e thread for your queries instead of following up on an old/closed e2e thread, new threads gets more attention than old threads and can provide link of old threads or information on the new post for clarity and faster response.

0 Yara Gowayed over 9 years ago in reply to Raja

Prodigy 40 points

Thank you for replying, I use the EVM board.
I wanted to actually change the frequency after booting, so this link is not really what I am searching for. Do you have any idea about the registers?

0 Raja over 9 years ago in reply to Yara Gowayed

TI__Guru* 81335 points

Yes. It is possible. You can implement it in your DSP application. Please refer below thread,

Thank you

0 Senthilkumar Srinivasan over 9 years ago

TI__Mastermind 43660 points

Yara,

1. There are three fields you can play around to change the core PLL frequency, PLL Multiplier, PLL Divider and Output Divider.

2. There is no way to change the core frequency without affecting the peripherals which are sourcing by SYSCLK1. Some peripherals may have their own prescale to change its frequency. Please refer particular peripheral user guide for more details.

Regards,
Senthil

0 Yara Gowayed over 9 years ago in reply to Senthilkumar Srinivasan

Prodigy 40 points

Okay, thank you!

0 Yara Gowayed over 9 years ago in reply to Raja

Prodigy 40 points

Thank you!

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66AK2H DSP frequency change