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256Mb: x4, x8, x16 SDRAM
256MSDRAM_E.p65
–
Rev. E; Pub. 3/02
Micron Technology, Inc., reserves the right to change products or specifications without notice.
2002, Micron Technology, Inc.
256Mb: x4, x8, x16
SDRAM
WRITE – DQM OPERATION
1
tCH
tCL
tCK
tRCD
DQM/
DQML, DQMU
CKE
CLK
A0-A9, A11, A12
DQ
BA0, BA1
A10
tCMS
tAH
tAS
ROW
BANK
ROW
BANK
ENABLE AUTO PRECHARGE
D
IN
m
+ 3
tDH
tDS
D
IN
m
D
IN
m
+ 2
tCMH
COMMAND
NOP
NOP
NOP
ACTIVE
NOP
WRITE
NOP
NOP
DON
’
T CARE
tCMS
tCMH
tDH
tDS
tDH
tDS
tAH
tAS
tAH
tAS
DISABLE AUTO PRECHARGE
tCKH
tCKS
COLUMN
m
2
T0
T1
T2
T3
T4
T5
T6
T7
NOTE:
1. For this example, the burst length = 4.
2. x16: A9, A11, and A12 =
“
Don
’
t Care
”
x8: A11 and A12 =
“
Don
’
t Care
”
x4: A12 =
“
Don
’
t Care
”
*CAS latency indicated in parentheses.
-7E
-75
SYMBOL*
t
CKS
t
CMH
t
CMS
t
DH
t
DS
t
RCD
MIN
1.5
0.8
1.5
0.8
1.5
15
MAX
MIN
1.5
0.8
1.5
0.8
1.5
20
MAX
UNITS
ns
ns
ns
ns
ns
ns
TIMING PARAMETERS
-7E
-75
SYMBOL*
t
AH
t
AS
t
CH
t
CL
t
CK (3)
t
CK (2)
t
CKH
MIN
0.8
1.5
2.5
2.5
7
7.5
0.8
MAX
MIN
0.8
1.5
2.5
2.5
7.5
10
0.8
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns