Type: Answers

Area: EMIF

Area: Intellectual Property


IP Product: DDR3 SDRAM Controller MegaCore supporting UniPHY

Why does mem_cke signal toggle when I assert local_self_rfsh_req signal on DDR3 SDRAM UniPHY based memory controller?

Description

When you assert local_self_rfsh_req on DDR3 SDRAM UniPHY based memory controller, you will notice mem_cke does not deassert, but it is pulsing like a clock signal.

Workaround/Fix

You will have to make a change in {instance_name}_controller_phy.sv file generated by the IP.

Scroll to line 448 and change 

.MEM_IF_CKE_WIDTH ( MEM_IF_CKE_WIDTH ),

To

.MEM_IF_CKE_WIDTH ( MEM_IF_CLK_EN_WIDTH ),

This issue will be fixed in a future version of the Quartus® II software.