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AR# 35661

MIG - All version - Spartan-6 - DDR3 - The MCB simulation model causes a warning in the simulation model.

Description

When I simulate my Spartan-6 MIG design the memory model gives the following warnings:

sim_tb_top.u_mem_c1.reset at time 22312501.0 ps WARNING: 200 us is required before RST_N goes inactive.


sim_tb_top.u_mem_c1.cmd_task at time 22463751.0 ps WARNING: 500 us is required after RST_N goes inactive before CKE goes active.

Solution

The first warning will occur if BYPASS_CALIBRATION is set to "NO" in the top level testbench.

sim_tb_top.u_mem_c1.reset at time 22312501.0 ps WARNING: 200 us is required before RST_N goes inactive.


To avoid this warning you can set BYPASS_CALIBRATION to "YES" in the testbench, this will cause simulation to take longer and does not affect the behavior of the memory model.

The second warning occurs because the MCB UNISIM model does not model this delay. 

There is no way to enable this for simulation but it does not affect the behavior of the memory model. 

This specification is properly observed in hardware.

Revision History:
08/13/2014 - Initial Released.
AR# 35661
Date Created 05/12/2010
Last Updated 08/13/2014
Status Active
Type General Article
Devices
  • Spartan-6
Tools
  • ISE Design Suite
IP
  • MIG Virtex-6 and Spartan-6