This configuration will not route completely because of the limited number of CMT Backbone routes available. The CMT BackBone hasfour routes available (see UG472 Figure 1-2) while this configuration requiresfive for the following signals:
- c0_sys_clk_p/n
- c0_freq_refclk
- c0_mem_refclk
- c0_sync_pulse
- c1_sys_clk_p/n
During implementation, the following warning will occur which will cause PAR to fail:
WARNING:Route:436 - The router has detected an unroutable situation for one or more connections. The router will finish the rest of the
design and leave them as unrouted. The cause of this behavior is either an issue with the placement or unroutable placement constraints.
To allow you to use FPGA editor to isolate the problems, the following is a list of (up to 10) such unroutable connections:
To work around the problem you must allocate one of the system clock pins to a CC_P/N pair in a different bank. This is an illegal configuration that MIG should not allow and will be fixed in MIG v1.6.