Device Family: Arria® V GT, Arria® V GX, Arria® V GZ, Arria® V ST, Cyclone® V E, Cyclone® V GT, Cyclone® V GX, Cyclone® V SE, Cyclone® V ST, Cyclone® V SX, Stratix® III, Stratix® IV E, Stratix® IV GT, Stratix® IV GX, Stratix® V E, Stratix® V GS, Stratix® V GT, Stratix® V GX

Type: Answers

Area: EMIF, Intellectual Property


IP Product: DDR3 SDRAM Controller Supporting UniPHY

What are the AC voltage levels that Quartus® II uses for DDR2 and LPDDR2 tDS and tIS set up derating ?

Description

The AC voltage levels depend on the value set in the Memory Parameters tab -> Memory Device Speed Grade and are shown below.

DDR2
AC250 for speed grades 200.0  & 266.667.
AC200 for speed grades 333.333, 400.0 & 533.333.

LPDDR2
AC300 for speed grade 200.0.
AC220 for speed grades 266.667, 333.333, 400.0 & 533.333.

In the Memory Timing tab, the values for parameters tIS (base) and tDS (base) should be selected from the external memory vendor device datasheet for the memory device speed grade (DDR2) or the data rate corresponding to the memory device speed grade (LPDDR2).

Workaround/Fix

This information is scheduled to be added to a future version of the External Memory Interface Handbook.