Hi,
How to set dsp speed to 375mhz? I referred to this linkhttps://e2e.ti.com/support/processors/f/791/p/112811/400040, and calculated through the cal spreadsheet. But the sysclk1 was not 375MHZ expected as Tai Ngeuyen said. So how to set sysclk1 to 375MHZ? Please help to provide correct parameters mentioned in the spreadsheet.
Hi Nancy,
I'm not sure you can obtain exactly 375MHz from 24MHz oscillator with the integer multiplier and integer dividers provided. The ratio from 375 to 24 is 15.625, or 125 / 8. To get exactly 375MHz, you'd have to multiply by 125x and divide by 8 with prediv and post div. Unfortinately the PLL multiplier tops out at 32x. Tai probably got 372MHz, which is the fastest the PLL can run while staying below the 375MHz limit.
If you really want 375MHz, I suggest you change the OSCIN from 24MHz to 30MHz. See output (using the latest spreadsheet from http://processors.wiki.ti.com/index.php/Programming_PLL_Controllers_on_OMAP-L1x8/C674x/AM18xx --> http://processors.wiki.ti.com/index.php/File:SYS_CLK_CALC_OMAP-L138_C674X_AM18X_v1p0.zip
Regards,
Mark
