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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
SINGLE WRITE – WITH AUTO PRECHARGE
1
NOTE:
1. For this example, the burst length = 1.
2. Requires one clock plus time (7ns to 7.5ns) with auto precharge or 14ns to 15ns with PRECHARGE.
3. x16: A9, A11, and A12 =
“
Don
’
t Care
”
x8: A11 and A12 =
“
Don
’
t Care
”
x4: A12 =
“
Don
’
t Care
”
4. WRITE command not allowed else
t
RAS would be violated.
*CAS latency indicated in parentheses.
-7E
-75
SYMBOL*
t
CMS
t
DH
t
DS
t
RAS
t
RC
t
RCD
t
RP
t
WR
MIN
1.5
0.8
1.5
37
60
15
15
1 CLK +
7ns
MAX
MIN
1.5
0.8
1.5
44
66
20
20
1 CLK +
7.5ns
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
–
120,000
120,000
TIMING PARAMETERS
-7E
-75
SYMBOL*
t
AH
t
AS
t
CH
t
CL
t
CK (3)
t
CK (2)
t
CKH
t
CKS
t
CMH
MIN
0.8
1.5
2.5
2.5
7
7.5
0.8
1.5
0.8
MAX
MIN
0.8
1.5
2.5
2.5
7.5
10
0.8
1.5
0.8
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ENABLE AUTO PRECHARGE
tCH
tCL
tCK
tRP
tRAS
tRC
tRCD
DQM/
DQML, DQMU
CKE
CK
A0-A9, A11, A12
DQ
BA0, BA1
A10
tCMH
tCMS
tAH
tAS
ROW
ROW
BANK
BANK
ROW
ROW
BANK
tWR
2
D
IN
m
COMMAND
tCMH
tCMS
NOP4
NOP4
NOP
ACTIVE
NOP4
WRITE
NOP
ACTIVE
tAH
tAS
tAH
tAS
tDH
tDS
tCKH
tCKS
NOP
NOP
COLUMN m
3
T0
T1
T2
T4
T3
T5
T6
T7
T8
T9
DON
’
T CARE