Datasheet

T
T
T
S
S
S
3
3
3
2
2
2
M
M
M
L
L
L
D
D
D
6
6
6
4
4
4
V
V
V
6
6
6
F
F
F
5
5
5
184PIN DDR266 Unbuffered DIMM
256MB With 32Mx8 CL2.5
SIMPLIFIED TRUTH TABLE (V=Valid, X=Don’t Care, H=Logic High, L=Logic Low)
COMMAND CKEn-1 CKEn
L H
L H
/CS /RAS /CAS
H H
X
H
X
Exit L
/WE BA 0,1 A 10 /AP
3
4
Write &
H 5
H X
H
A 0 ~A 9, A 11, A 12 Note
Register
Auto Precharge Disable
Column Address
H X
Entry H
Active Power Down
X X
Extended
Mode Register Set
H
H X X
L H L
H X
L
X L L
X 3
L
L V
X X
X
L
L L OP CODE 1,2
Bank Active & Row Addr. H X
4
Column
Address
(A 0 ~A 9 )
V V V
Register Mode Register Set H X L L L L OP CODE
Auto Refresh H
H L
L L H H V Row Address
Auto Precharge Enable
Burst Stop H X L H H L
L V V V
X X X X
Precharge Power
Down Mode
DM H X X 8
X X 9
No Operation Command H
L
X
1,2
Refresh
H
4, 6
Exit L H
H X
X
3
H X
Auto Precharge Disable
Read &
Column Address
H
X 7
Entry L
L H V
H X L
X X X
X
9
Note:
1. OP Code: Operand Code. A0 ~ A12 & BA0 ~ BA1: Program keys. (@EMRS/MRS)
L L
3
4
L
X
5. If A10/AP is "High" at row precharge, BA0 and BA1 are ignored and all banks are selected.
6. During burst write with auto precharge, new read/write command cannot be issued. Another bank read/write command can be issued
after the end of burst. New row active of the associated bank can be issued at tRP after the end of burst.
7. Burst stop command is valid at every burst length.
Self
Refresh
X L H
Bank Selection
Precharge
H
H L
Exit
Auto Precharge Enable
All Banks
L H H H
8. DM sampled at the rising and falling edges of the DQS and Data-in is masked at the both edges (Write DM latency is 0).
9. This combination is not defined for any function, which means "No Operation (NOP)" in DDR SDRAM.
L Column
Address
(A
0 ~A 9 )
V
L H L
2. EMRS/ MRS can be issued only at all banks precharge state.
3. Auto refresh functions are same as the CBR refresh of DRAM. The automatic precharge without row precharge command is meant by
"Auto". Auto/self refresh can be issued only at all banks precharge state.
4. BA0 ~ BA1: Bank select addresses. If both BA0 and BA1 are "Low" at read, write, row active and precharge, bank A is selected. If both
BA0 is "High" and BA1 is "Low" at read, write, row active and precharge, bank B is selected. If both BA0 is "Low" and BA1 is "High" at
read, write, row active and precharge, bank C is selected. If both BA0 and BA1 are "High" at read, write, row active and precharge, bank
D is selected.
Entry
H H H
Transcend Information Inc.
9