W949D6DB Datasheet, PDF (30/60 Pages) Winbond – Standard Self Refresh Mode

W949D6DB / W949D2DB
8.5.3 Read Burst Showing CAS Latency
CK
CK
Command
READ
NOP
NOP
NOP
NOP
NOP
Address BA Col n
DQS
CL=2
DQ
DQS
DO n
CL=3
DQ
DO n
= Don't Care
1) DO n = Data Out from column n
2) BA, Col n = Bank A, Column n
3) Burst Length = 4; 3 subsequent elements of Data Out appear in the programmed order following DO n
4) Shown with nominal tAC, tDQSCK and tDQSQ
8.5.4 Read to Read
Data from a read burst may be concatenated or truncated by a subsequent READ command. The first
data from the new burst follows either the last element of a completed burst or the last desired element
of a longer burst that is being truncated. The new READ command should be issued X cycles after the
first READ command, where X equals the number of desired data-out element pairs (pairs are required
by the 2n-prefetch architecture). This is shown in following figure.
8.5.5 Consecutive Read Bursts
CK
CK
Command
Address
READ
BA,Col n
DQS
DQ
DQS
DQ
NOP
CL=2
READ
BA,Col b
NOP
DO n
CL=3
DO n
NOP
DO b
NOP
DO b
1) DO n (or b) = Data Out from column n (or column b)
= Don't Care
2) Burst Length = 4 or 8 (if 4, the bursts are concatenated; if 8, the second burst interrupts the first)
3) Read bursts are to an active row in the bank
4) Shown with nominal tAC, tDQSCK and tDQSQ
- 30 -
Publication Release Date: Oct. 08, 2014
Revision: A01-003