Device Family: Stratix® V E, Stratix® V GS, Stratix® V GT, Stratix® V GX

Type: Answers

Area: EMIF, Intellectual Property


IP Product: DDR3 SDRAM Controller MegaCore supporting UniPHY

ODT signal does not toggle when ODT Rtt nominal is off and Dynamic ODT (Rtt_wr) is on

Description

This affects DDR3 SDRAM memory controllers in Stratix® V devices.

ODT signal does not toggle if in the DDR3 SDRAM MegaWizard™ GUI the value of ODT Rtt nominal is selected to 'ODT disabled'. When ODT nominal is disabled then no matter what value you select for Dynamic ODT, the ODT signal does not toggle.

Workaround/Fix

Make sure you select the same RZQ value for \'ODT Rtt nominal\' and \'Dynamic ODT\'.