C6657 of SPI clock rate at the SPI boot

kenshow

Hi,

I'll use SPI boot of C6657.
What is the clock frequency of SPI at the first access before RBL is set the user frequency from parameter table of SPI ROM?

Regards,
Kenshow

over 12 years ago

0 HRi over 12 years ago

Guru 10750 points

Hi Kenshow,

SYSCLK7 is the input clock to the SPI module, please note that the SPI is in reset state at system startup and the RBL SW take's it out of reset,

Thanks,

0 kenshow over 12 years ago in reply to HRi

Genius 3725 points

Thanks HR,

I would like to know SPICLK output frequency as first access to SPI memory.

I think that RBL set the default frequency of SPICLK. And, RBL change the frequency after reading parameter table of SPI memory for user setting. I would like to know the default frequency before user setting. Is it half of SYSCLK? unfortunately, I don't know it because we cannot get RBL code of C6657.

Regards,
Kenshow

0 HRi over 12 years ago in reply to kenshow

Guru 10750 points

Hi Kenshow,

At reset the SPI Prescale (SPIFMTn) is equal to "0" which means that SPICLK is equal to SPI module clock/2, the SPI module clock is SYSCLK7 which is equal to SYSCLK/6,

Thanks,

0 Rahul Prabhu over 12 years ago in reply to HRi

TI__Guru** 116170 points

Hi Kenshow,

The default SPI bus frequency for first access as set by the ROM is 500 Khz. We provide the ROM code for the C6678 devices which is same as the C6657 devices on the following wiki. Please look at the nysh.h and tiboot.h file under devices to look at the default settings in the parameter table.

http://processors.wiki.ti.com/index.php/Keystone_Device_Architecture

We will plan to add this to the device documentation but currently these details.

Regards,

Rahul

0 kenshow over 12 years ago in reply to Rahul Prabhu

Genius 3725 points

Hi Rahul and HR,

Thanks for your useful information.

Regards,
Kenshow

Processors

Processors forum

C6657 of SPI clock rate at the SPI boot