Figure 6-19: Delay Chains in an I/O Block
D5 OCT
delay
chain
OCT Enable Output Enable
D5
output-enable
delay chain
D5 Delay
delay
chain
D1 Delay
delay chain
0
1
DQ or DQS
Each DQS logic block contains a delay chain after the
dqsbusout
output and another delay chain before the
dqsenable
input.
Figure 6-20: Delay Chains in the DQS Input Path
DQS
Enable
dqsin
dqsenable
DQS
Enable
Control
DQS delay
chain
dqsbusout
DQS
T11
delay
chain
Related Information
•
ALTDQ_DQS2 Megafunction User Guide
Provides more information about programming the delay chains.
•
on page 6-25
I/O and DQS Configuration Blocks
The I/O and DQS configuration blocks are shift registers that you can use to dynamically change the settings
of various device configuration bits.
• The shift registers power-up low.
Altera Corporation
External Memory Interfaces in Cyclone V Devices
6-29
I/O and DQS Configuration Blocks
CV-52006
2014.01.10