Type: Answers

Area: EMIF, Intellectual Property


IP Product: Renewal RLDRAM II Controller

Is there a known issue with timing constraints generated by RLDRAMII UniPHY based IP in Quartus II software version 11.0SP1?

Description

Yes. there is an issue with how the RLDRAMII UniPHY based IP interprets the board skew parameters in Quartus® II software 11.0SP1. The board skew parameters are not properly entered in the {core_name}_p0_timing.tcl file.

 

For example, If you enter 20ps for “Average delay difference between Address/Command and CK, the <core_name>_p0_timing.tcl script properly constrains it with the following constraint

 

set board(addresscmd_CK_skew) [expr { 20 / 1000.0 }]

 

But if you enter 20ps for “Maximum skew within Address/Command bus”, the

{core_name}_p0_timing.tcl puts the following incorrect constraint. 

 

set board(intra_addr_ctrl_skew) [expr { 0.02 / 1000.0 }]

 

This constraint implies that the skew is 0.02ps instead of 20ps for the parameter.

 

To workaround this issue, make the change manually and change the constraint to:

 

set board(intra_addr_ctrl_skew) [expr { 20 / 1000.0 }]

 

This issue will be fixed in the future version of the Quartus II software and the IP.