No. ARM, SDRAM and GPU each have their own PLLs can can be unrelated frequencies.thelightguy wrote:Cool! I wasn't sure if the RAM speed had to be an integer multiple of anything like the various GPU timings.
The GPU core, h264, v3d and isp share a PLL, so need to have related frequencies.
Looking at the code, the PLL will be set to:
pll_freq = core_freq * 2^n, for smallest n satisfying pll_freq > 600MHz.
GPU core, h264, v3d and isp should all be integer divisors of PLL freq.
So if core_freq=480, then pll_freq=960. That would allow a v3d_freq of 320 with an integer divider.