AR# 53061

14.3 EDK, DDRx - "ERROR: tCK(avg) maximum violation by 33.335938 ps"

Description

If I am simulating XPS Base System Builder designs containing the AXI DDR IP, tck error messages similar to the following occur on the simulator console:

"system_tb.inst_ddr_00.main: at time 76820837.0 ps ERROR: tCK(avg) maximum violation by 33.335938 ps"

How can I fix this?

Solution

This error occurs if the clock frequency driving the DDR3 device is lower than the DDR3 JEDEC specification value of 303 MHz:

ddr3_jedec_spec.jpg
ddr3_jedec_spec.jpg

In many of the Base System Builder projects, this will be set to 300 MHz, causing a mismatch that leads to tck errors.

This can be ignored in the simulation since the IP allows for this margin.

AR# 53061
Date 11/26/2012
Status Active
Type General Article
Tools
IP