Varible clock rate

Hi Geri,

for whatever rate value you choose, the final rate will tend to be correct over time despite the irregular nature of enable. This is a matter of accum. resolution and design toloerances but 32 bits is pretty high for most.

You can if you wish use a dedicated accum for a given ratio e.g. for 20MHz on 25MHz you have two choices:

generic high resolution accum: modulo 2 above then:

20 = 25 * incr/2^32 then incr = 2^32 * 20/25 = 2^32 * 0.80000...

option 2:

dedicated accum: i.e. incr = 20, accum 0~24

or incr = 4, accum = 0~4 (in effect a divider)