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• Differential or complementary DQS signaling—the maximum number of data pins per group decreases
by one.
• DDR3 and DDR2 interfaces—each x8 group of pins require one DQS pin. You may also require one
DQSn pin and one DM pin. This further reduces the total number of data pins available.
Table 6-4: DQ/DQS Bus Mode Pins for Cyclone V Devices
Maximum Data Pins per Group
Data Mask
(Optional)
DQSn Support
Mode
11
Yes
Yes
x8
23
Yes
Yes
x16
External Memory Interfaces in Cyclone V Devices
Altera Corporation
CV-52006
DQ/DQS Bus Mode Pins for Cyclone V Devices
6-4
2014.01.10