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AN6017 - Differences in Implementation of 65 nm QDR™ II/DDR II and QDR II+/DDR II+ Memory Interfaces | Cypress Semiconductor

AN6017 - Differences in Implementation of 65 nm QDR™ II/DDR II and QDR II+/DDR II+ Memory Interfaces

Last Updated: 
Nov 23, 2015
This document describes the following:
  • Description of the QDRII+/DDRII+ devices
  • Differences between QDRII/DDRII and QDRII+/DDRII+ functionality and timing
  • Design changes that need to be considered by system designers when migrating from QDRII/DDRII to QDRII+/DDRII+ devices


The table below outlines the differences between the QDRII/DDRII and QDRII+/DDRII+ SRAMs

Differences between QDRII / DDRII and QDRII+ / DDRII+

Frequency (PLL enabled)-65nm technology device

120 MHz ~ 333 MHz

120 MHz ~ 550 MHz Burst of 2 QDRII+/DDRII+ support 333
MHz and Burst of 4 QDRII+/DDRII+
support 550 MHz as highest frequency.
Organization x8, x9, x18, x36 x18, x36 -
VDD 1.8 V ± 0.1 V 1.8 V ± 0.1 V -
VDDQ 1.8 V ± 0.1 V or 1.5 V ± 0.1 V 1.8 V ± 0.1 V or 1.5 V ± 0.1 V -
Read latency 1.5 clocks 2.0 & 2.5 clocks QDRII+/DDRII+ read latency is not user selectable. Offered as two different devices.
Input clocks Single ended (K,K#) Single ended     (K,K#) -
Output clocks (C,C#) Yes No -
ODT (On-Die Termination) No Offered in ODT and Non ODT versions -
A0 (DDR B2) Yes No -
A0, A1 (DDR B4) Yes No -
Echo clock number 1 Pair 1 Pair Echo clocks are single ended
PKG 165 ball FBGA 165 ball FBGA -
Individual byte write (BW0#, BW1#) Yes Yes -


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