TMS320C6748: Which PLL0 parameters may i select?

Juan Encinas

Part Number: TMS320C6748

Hi,

I was wondering if someone could tell me what to consider when choosing the pre-div, multiplier and post-div of the PLL0 because as i see it... I would get the same clock output with many diferent combinations fo those parameters and the clock source frequency.

Could you tell me which ranges should i select or not for each parameter and for the clock source? (for the tms320c6748)

I might be wrong but without a warning of the tool i could make a cpu clock with a higher frequency than the maximun freq specified in the data sheet (456MHz) and i tested and it Works at that freq without problem, so i'm a bit confused. It's the datasheet wrong? It's just the maximun recomendable freq(how restrictive is)? It's not related with the CPU freq?

Sorry for how bad i explain myself.

Thanks in advance,

Juan

over 7 years ago

0 Yordan Kovachev over 7 years ago

TI__Guru**** 161600 points

Hi,

This tool is obsolete. I'd recommend using the latest TI SDKs.

You can have a look at this wiki:
processors.wiki.ti.com/.../Building_PSP_Components_for_OMAP-L1x_on_v3.x_Kernel

Also this one:
processors.wiki.ti.com/.../MCSDK_User_Guide_for_OMAPL138

Best Regards,
Yordan

0 Juan Encinas over 7 years ago in reply to Yordan Kovachev

Intellectual 510 points

Hi Yordan,

Maybe I didn't explain the situation well.

I'm using and SDK to develope the code and to debug it, but i need to load the program in the flash, so i used the AISgen tool I mention before.

What i was asking is if you could tell me which are the recomended values (or range of values) of each parameters of the PLL0 configuration and the clock source.

Because I see lots of images like the one that appears in the first link you suggested with some parameters but without any explanation about why to choose that ones.

Thanks in advance,

Juan

0 Sahin Okur over 7 years ago in reply to Juan Encinas

TI__Mastermind 27355 points

Hi Juan,

Please refer to the following wiki page:

0 Juan Encinas over 7 years ago in reply to Sahin Okur

Intellectual 510 points

Thanks, that was helpful.
Now my only question if how do i know if the clock source of the tms320c6748 is a crystal or an oscillator and its frequency?

Thanks in advance,
Juan

0 Yordan Kovachev over 7 years ago in reply to Juan Encinas

TI__Guru**** 161600 points

Hi Juan,

You can check your EVM schematics and see what is connected and its frequency in part datasheet. For example for TMS320C6748 LCD you can check its schematics and see what part is connected to the OSCIN/OSCOUT pins by checking its schematics:
www.ti.com/.../getliterature.tsp

Best Regards,
Yordan

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TMS320C6748: Which PLL0 parameters may i select?