GP32 Questions Re. Clocks


velvetfr

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Hi,

I am currently designing some functions to set the clock registers of the GP32. When reading the Samsung Arm920T manual, I see that there is a limit for HCLK and PCLK of 66MHz, which in fact limit also FCLK (due to the fact that FCLK is used as a master clock for HCLK and PCLK) to 132MHz ... what is about this 166MHz overclocking, and I assume that this trick do not respect this limit of 66MHz for HCLK and PCLK ? Am I right, or miss something ?

Thanks,
velvetfr
 
You are right.

To run the CPU at 166MHz, you set FCLK (also known as MCLK) to 166MHz, and the H-divider is 2, so HCLK is 83MHz. This is outside the specified range, which is why it's called overclocking :)

Note that you can also set the PCLK divider (from HCLK) to 1 or 2, so at 166MHz PCLK can be 83MHz or 41MHz. Most programs that I've seen set it to 83MHz.
 
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