AR #33724 - 11.3 EDK - WARNING:EDK - : mpmc_0 (mpmc) - Could not determine clock frequency on input
11.3 EDK - WARNING:EDK - : mpmc_0 (mpmc) - Could not determine clock frequency on input
| AR# | 33724 |
| Part | EDK-IP-Memory-MPMC |
| Last Modified | 2009-10-28 00:00:00.0 |
| Status | Active |
| Keywords | dcm, ethernet, temac, ddr |
Description
Keywords: dcm, ethernet, temac, ddr
When using an EDK design clocked by a dcm_module, one of the following warnings occur. How do I resolve this issue?
WARNING:EDK - : mpmc_0 (mpmc) - Could not determine clock frequency on input clock port MPMC_Clk0, not performing clock DRCs.
WARNING:EDK - : mpmc_0 (mpmc) - Could not determine clock frequency on input clock port MPMC_Clk_200Mhz, not performing clock DRCs.
Performing Clock DRCs...
INFO:EDK:1038 - Did not implement clock DRCs for parameter:
xps_ethernetlite_0:C_SPLB_CLK_PERIOD_PS. Top-level frequency could not be propagated to this IP. Please make sure that you have specified the frequency of the top-level clock port, and that the clocks are properly connected.
INFO:EDK:1038 - Did not implement clock DRCs for parameter:
xps_mch_emc_0:C_MCH_SPLB_CLK_PERIOD_PS. Top-level frequency could not be propagated to this IP. Please make sure that you have specified the frequency of the top-level clock port, and that the clocks are properly connected.
INFO:EDK:1038 - Did not implement clock DRCs for parameter:
mpmc_0:C_MPMC_CLK0_PERIOD_PS. Top-level frequency could not be propagated to this IP. Please make sure that you have specified the frequency of the top-level clock port, and that the clocks are properly connected.
INFO:EDK:1038 - Did not implement clock DRCs for parameter:
mpmc_0:C_MPMC_CLK_MEM_PERIOD_PS. Top-level frequency could not be propagated to this IP. Please make sure that you have specified the frequency of the top-level clock port, and that the clocks are properly connected.
INFO:EDK:783 - Clock frequency could not be propagated to the port: MPMC_Clk0 in IP: mpmc_0 - Clock Ratio DRC will not be performed.
Solution
This is caused by the dcm_module not propagating the FREQUENCY attribute on its CLKIN port to its output ports. Without the FREQUENCY tag, IP cores connected to the clock cannot determine their clock rate.It is recommended to replace the dcm_module with the clock_generator core, which correctly propagates the FREQUENCY attribute to its output clocks.