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Read data capture clock association – Altera RLDRAM II Controller MegaCore Function User Manual

Page 20

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2–10

MegaCore Version 9.1

Altera Corporation

RLDRAM II Controller MegaCore Function User Guide

November 2009

Block Description

rldramii_dq[8:0]

is captured by the delayed

rldramii_qk[0]

rldramii_dq[17:9]

is captured by the delayed

rldramii_qk[1]

rldramii_dq[26:18]

is captured by the delayed

rldramii_qk[2]

rldramii_dq[35:27]

is captured by the delayed

rldramii_qk[3]

QVLD is always captured by the delayed version of
rldramii_qk[0]

for the associated RLDRAM II device. In

Figure 2–6

there are four rldramii_qk[] signals. Only

rldramii_qk[0]

per RLDRAM II device captures the associated

QVLD signal:

rldramii_qvld[0]

is captured by the delayed

rldramii_qk[0]

rldramii_qvld[1]

is captured by the delayed

rldramii_qk[2]

After the capture registers all captured read data is clocked off the
undelayed rldramii_qk[] signal that captures the QVLD signal
for a particular RLDRAM II device:

All RLDRAM II 0 captured data is clocked off the undelayed
rldramii_qk[0]

All RLDRAM II 1 captured data is clocked off the undelayed
rldramii_qk[2]

Only one capture_clk[] per attached RLDRAM II device is
output from the datapath:

RLDRAM II 0 capture data is associated with
capture_clk[0]

, which is the delayed rldramii_qk[0]

RLDRAM II 1 capture data is associated with
capture_clk[1]

, which is the delayed rldramii_qk[2]

Read Data Capture Clock Association

Figure 2–7

shows the read data and data strobes at the memory interface

for the example datapath in

Figure 2–6

.

Figure 2–8

shows how the

capture_clk[]

associates with the captured read data,

control_rdata[]

at the datapath interface.