An error appears when the ISE is routing the layout.
There are two possible reasons for the "Clock_dedicated_route" error:
1. There is a clock you do not put to the global clock or local clock pin, the layout can not be used as a clock to allocate resources.
2. Is you want to output a clock signal on Io, but you do not use the correct method, such as in Spartan6 you must use the ODDR register output, and not directly to the clock to a direct connection to the IO signal.
Here's how to fix it:
1. The simplest is to add a pin "PIXCLK_BUFG" directly. O "Clock_dedicated_route = FALSE;
2. Select a dedicated clock pin;
3. Select the ODDR register to output the clock signal on the IO pin.
In short, you use the signal or your method does not conform to the default clock resource usage rules. Once again despise Spartan 6 of the film, there are many bugs, and you need to constantly update the ISE version, a lot of problems may be the new Ise can be solved, and do not need you to contemplate.
Error:place:1136-this design contains a global buffer instance ... non-clock load pins off chip