How to Change ARM Clock for K2E EVM

Tsutomu Furuse

Hi.

Would you please tell me how to change the ARM clock frequency for K2E EVM?

For K2H EVM, we can change it with the following U-Boot command as explained at TI Wiki.

pllset arm <mult> <div> <OD>

However, The pllset command for K2E does not have "arm" selection but "pa" or "ddr3".
The Wiki article mentioned that ARM cores of K2E are clocked by the main PLL. So I suppose we should modify the PLL setting of the main PLL for the ARM clock. It seems that "pa" is not for the main PLL.

arch/arm/cpu/armv7/keystone/cmd_clock.c

arch/arm/cpu/armv7/keystone/clock.c

Best regards,
Tsutomu Furuse

over 10 years ago

0 Senthilkumar Srinivasan over 10 years ago

TI__Mastermind 43660 points

Hello Tsutomu,

There is no separate PLL for ARM corepac in the K2E devices. The Core/Main PLL is common for both DSP and ARM corepacs.

If you want to change the ARM clock frequency, you need to change the main PLL parameters but it will effect both DSP and ARM frequency. The PA PLL is for packet accelerator and it has no connection with ARM.

Regards,
Senthil

0 Tsutomu Furuse over 10 years ago in reply to Senthilkumar Srinivasan

Expert 1435 points

Senthil,

Thank you for your reply.

The pllset command of K2E U-Boot has "pa" and "ddr3" selections only. So I understand that we need to make a program to configure the K2E ARM clock. Right?
Or are there any other command to configure the ARM clock? I prefer commands work for Linux.

Best regards,
Tsutomu Furuse

0 Titusrathinaraj Stalin over 10 years ago in reply to Tsutomu Furuse

TI__Guru** 116100 points

Hi Tsutomu,
We don't have a option to change the ARM clock in u-boot through "pllset" command for K2E board.
You have to modify the u-boot code if you want to change the ARM.
Why do you want to change the ARM in runtime ?

0 Tsutomu Furuse over 10 years ago in reply to Titusrathinaraj Stalin

Expert 1435 points

Titus,

Thank you for your reply.

One of my customers wants to modify the ARM clock frequency to evaluate the K2E power consumption at varying frequencies. So if she can change the ARM clock in boot time, it is OK for her.

Best regards,
Tsutomu Furuse

0 Titusrathinaraj Stalin over 10 years ago in reply to Tsutomu Furuse

TI__Guru** 116100 points

Hi,
You can change the "spl_pll_config" structure entry in the following file.

board/ti/ks2_evm/board_k2e.c

Ex:

From
{ CORE_PLL, 16, 1, 2 }, //800MHz
To
{ CORE_PLL, 20, 2, 2 }, //1GHz

Select any one of the frequency from the following entry.

static struct pll_init_data core_pll_config[] = {
{ CORE_PLL, 16, 1, 2 }, /* 800 */
{ CORE_PLL, 17, 1, 2 }, /* 850 */
{ CORE_PLL, 20, 2, 2 }, /* 1000 : 1GHz*/
{ CORE_PLL, 25, 1, 2 }, /* 1250 */
{ CORE_PLL, 27, 1, 2 }, /* 1350 */
{ CORE_PLL, 28, 2, 2 }, /* 1400 */
{ CORE_PLL, 30, 1, 2 }, /* 1500 */
};

0 Tsutomu Furuse over 10 years ago in reply to Titusrathinaraj Stalin

Expert 1435 points

Titus,

Thank you very much for the solution.
Although I have not tried it yet, it will be much of help for me.

Best regards,
Tsutomu Furuse

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How to Change ARM Clock for K2E EVM