AS4C256M16D3
Read Timing; Data Strobe to Data Relationship
The Data Strobe to Data relationship is shown in the following figure and is applied when the DLL and enabled
and locked.
Rising data strobe edge parameters:
- tDQSQ describes the latest valid transition of the associated DQ pins.
- tQH describes the earliest invalid transition of the associated DQ pins.
Falling data strobe edge parameters:
- tDQSQ describes the latest valid transition of the associated DQ pins.
- tQH describes the earliest invalid transition of the associated DQ pins.
- tDQSQ; both rising/falling edges of DQS, no tAC defined
tDQSQ; both rising/falling edges of DQS, no tAC defined
Figure 20. Data Strobe to Data Relationship
CK#
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
NOP
CK
Notes 3
READ
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
COMMAND
RL = AL +CL
Notes 4
Bank,
Col n
ADDRESS
tDQSQ (max)
tDQSQ (max)
tRPST
DQS,DQS#
Notes 2
tRPRE
tQH
tQH
DQ
Dout
n
Dout
n+1
Dout
n+4
Dout
n+2
Dout
n+3
Dout
n+5
Dout
n+6
Dout
n+7
(Last data valid)
Notes 2
Dout
n
Dout
n+1
Dout
n+4
Dout
n+2
Dout
n+3
Dout
n+5
Dout
n+6
Dout
n+7
DQ
(First data no longer valid)
Dout
n
Dout
n+1
Dout
n+2
Dout
n+3
Dout
n+4
Dout
n+5
Dout
n+6
Dout
n+7
All DQs collectively
NOTES:
TRANSITIONING DATA
Don't Care
1. BL = 8, RL = 5 (AL = 0, CL = 5)
2. DOUT n = data-out from column n.
3. NOP commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ command at T0.
5. Output timings are referenced to VDDQ/2, and DLL on for locking.
6. tDQSQ defines the skew between DQS,DQS# to Data and does not define DQS,DQS# to Clock.
7. Early Data transitions may not always happen at the same DQ. Data transitions of a DQ can vary (either early or late) within a burst.
Confidential
44
Rev. 3.0
Aug. /2014
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
