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Figure 6-15: Avoiding Glitch on a Non-Consecutive Read Burst Waveform
This figure shows how to avoid postamble glitches using the HDR block.
Delayed by
1/2T logic
Preamble
Postamble
Postamble glitch
DQS
Postamble Enable
dqsenable
Dynamic OCT Control
The dynamic OCT control block includes all the registers that are required to dynamically turn the on-chip
parallel termination (R
T
OCT) on during a read and turn R
T
OCT off during a write.
Figure 6-16: Dynamic OCT Control Block for Cyclone V Devices
DFF
D
Q
D
Q
DFF
OCT Control
OCT Control
OCT Half-Rate Clock
0
1
D
Q
DFF
D
Q
DFF
1
0
Write Clock
OCT Enable
OCT Control Path
The full-rate write clock comes from the PLL. The DQ write
clock and DQS write clock have a 90° offset between them
Related Information
Dynamic OCT in Cyclone V Devices
on page 5-40
Provides more information about dynamic OCT control.
IOE Registers
The IOE registers are expanded to allow source-synchronous systems to have faster register-to-FIFO transfers
and resynchronization. All top, bottom, and right IOEs have the same capability.
External Memory Interfaces in Cyclone V Devices
Altera Corporation
CV-52006
Dynamic OCT Control
6-26
2014.01.10