GCLK overmapped

Hello,

From searching, I see that others have had this same problem, but the solutions were vague and old (2002). I'm using XPS 8.1 with Spartan IIE 600 and I'm trying to bring a couple of signals from a peripheral to a pin, but XPS automatically assumes that they are clocks, so it uses a GCLK which results in the error:

"Number of GCLKs: 5 out of 4 125% (OVERMAPPED)".

How can I find out which signals it has routed as GCLKs? How can I reduce the number of GCLKs used? How can I manually assign GCLKs to the signals I want, without XPS doing it automatically?

I've tried passing the signals through an OBUF in the wrapper of my peripheral, but that results in an "illegal buffer" error.

Thanks for your help.

Reply to
markmcmahon
Loading thread data ...

This information is from ISE9.2i, Spartan 3e target.

In the GUI, bring up the design summary. Under "Design Overview" in the Design summury window. Click on "CLOCK REPORT" If a clock is listed as beign in Resource BUFGMUX_*, It is being assigned to GCLK.

I don't know.

Xilinx Constraint User Guide(P191 of 396) (UCF) INST "buf1" LOC=GCLKBUF1;

Reply to
Dwayne Dilbeck

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.