Do you know how to reconfig the DFS of Spartan DCM at runtim

[patcher]

Do you know how to reconfigurate the DFS of Spartan DCM at runtime?

I would like to change the FXMULTIPLY AND FXDIVIDE in order to get
different CLKFX at runtime. According to xilinx manual it's not
possible.

But probabely smbd has just a good idea?

PS: a simple reload of the FPGA configuration is too slow...

 

[Sean Durkin]

patcher wrote:

Do you know how to reconfigurate the DFS of Spartan DCM at runtime?

I would like to change the FXMULTIPLY AND FXDIVIDE in order to get
different CLKFX at runtime. According to xilinx manual it's not
possible.

But probabely smbd has just a good idea?

PS: a simple reload of the FPGA configuration is too slow...
Does the Spartan 3 have BUFGMUXes like the Virtex-II Pro? If so, you

could it it differently alltogether... Use two DCMs to create the two
clocks you want to switch between, and feed them into the two inputs of
a BUFGMUX... then you could just chose the desired output clock by
changing the select signal.... not sure what happens to attached logic
during the switch, though...

cu,
Sean