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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
ALTERNATING BANK READ ACCESSES
1
ENABLE AUTO PRECHARGE
tCH
tCL
tCK
tAC
tLZ
DQM/
DQML, DQMU
CLK
A0-A9, A11, A12
DQ
BA0, BA1
A10
tOH
D
OUT
m
tCMH
tCMS
tAH
tAS
tAH
tAS
tAH
tAS
ROW
ROW
ROW
ROW
DON
’
T CARE
UNDEFINED
tOH
D
OUT
m
+ 3
tAC
tOH
tAC
tOH
tAC
D
OUT
m
+ 2
D
OUT
m
+ 1
COMMAND
tCMH
tCMS
NOP
NOP
ACTIVE
NOP
READ
NOP
ACTIVE
tOH
D
OUT
b
tAC
tAC
READ
ENABLE AUTO PRECHARGE
ROW
ACTIVE
ROW
BANK 0
BANK 0
BANK 3
BANK 3
BANK 0
CKE
tCKH
tCKS
COLUMN
m
2
COLUMN
b
2
T0
T1
T2
T4
T3
T5
T6
T7
T8
tRP - BANK 0
tRAS - BANK 0
t
RC - BANK 0
tRCD - BANK 0
tRCD - BANK 0
CAS Latency - BANK 0
tRCD - BANK 1
CAS Latency - BANK 1
t
RRD
NOTE:
1. For this example, the burst length = 4, and the CAS latency = 2.
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
CMH
t
CMS
t
LZ
t
OH
t
RAS
t
RC
t
RCD
t
RP
t
RRD
MIN
0.8
1.5
1
3
37
60
15
15
14
MAX
MIN
0.8
1.5
1
3
44
66
20
20
15
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
120,000
120,000
TIMING PARAMETERS
-7E
-75
SYMBOL*
t
AC (3)
t
AC (2)
t
AH
t
AS
t
CH
t
CL
t
CK (3)
t
CK (2)
t
CKH
t
CKS
MIN
MAX
5.4
5.4
MIN
MAX
5.4
6
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
0.8
1.5
2.5
2.5
7
7.5
0.8
1.5
0.8
1.5
2.5
2.5
7.5
10
0.8
1.5