Datasheet

Read Operation
Read Timing Definitions
Read timings are shown below and are applicable in normal operation mode, i.e. when the DLL is enabled and
locked.
Rising data strobe edge parameters:
 t
DQSCK
min/max describes the allowed range for a rising data strobe edge relative to CK, CK#.
 t
DQSCK
is the actual position of a rising strobe edge relative to CK, CK#.
 t
QSH
describes the DQS, DQS# differential output high time.
 t
DQSQ
describes the latest valid transition of the associated DQ pins.
 t
QH
describes the earliest invalid transition of the associated DQ pins.
Falling data strobe edge parameters:
 t
QSL
describes the DQS, DQS# differential output low time.
 t
DQSQ
describes the latest valid transition of the associated DQ pins.
 t
QH
describes the earliest invalid transition of the associated DQ pins.
t
DQSQ
; both rising/falling edges of DQS, no t
AC
defined.
t
DQSCK
DQS#
DQS
t
DQSCK
t
QSH
t
QSL
Associated
DQ Pins
t
QH
t
QH
t
DQSQ
t
DQSQ
t
DQSCK min
t
DQSCK max
Rising Strobe
Variance
Windown
t
DQSCKi
Rising Strobe
Variance
Windown
t
DQSCKi
Rising Strobe
Variance
Windown
t
DQSCKi
CK#
CK
t
DQSCK max
t
DQSCK center
t
DQSCK min
t
DQSCK min
Rising Strobe
Variance
Windown
t
DQSCKi
Rising Strobe
Variance
Windown
t
DQSCKi
Rising Strobe
Variance
Windown
t
DQSCKi
Figure 86. READ Timing Definition
AS4C256M16D4
Confidential
- 90 of 201 -
Rev.1.0 Aug.2019