MB81F641642D Fujitsu Microelectronics, MB81F641642D Datasheet - Page 42

• Manufacturer Part Number: MB81F641642D
• Description: 4 x 1M x 16-Bit SDRAM
• Manufacturer: Fujitsu Microelectronics

42
MB81F641642D-75/-102/-102L
A
CLK
Command
Notes: *1. All banks should be precharged prior to the first Auto-refresh command (REF).
CLK
CKE
Command
Notes: *1. Precharge command (PRE or PALL) should be asserted if any bank is active prior to Self-refresh Entry command (SELF).
12
, A
13
*2. Bank select is ignored at REF command. The refresh address and bank select are selected by internal refresh counter.
*3. Either NOP or DESL command should be asserted during t
*4. Any activation command such as ACTV or MRS command other than REF command should be asserted after t
*2. The Self-refresh Exit command (SELFX) is latched after t
*3. Either NOP or DESL command can be used during t
*4. CKE should be held high within one t
(
BA)
last REF command.
conjunction with CKE.
DON’T CARE
NOP
TIMING DIAGRAM – 16 : SELF-REFRESH ENTRY AND EXIT TIMING
REF
*1
*1
*2
TIMING DIAGRAM – 15 : AUTO-REFRESH TIMING
SELF
t
SI
NOP
(min)
*3
RC
t
DON’T CARE
period after t
RC
NOP
(min)
*3
CKSP
RC
period.
.
NOP
RC
CKSP
NOP
t
period while Auto-refresh mode.
CKSP
*3
(min). It is recommended to apply NOP command in
*2
(min)
Preliminary (AE4.1E)
DON’T CARE
SELFX
REF
*2
t
RC
NOP
(min)
NOP
t
*3
RC
*4
(min)
Command
*3
Command
BA
RC
from the
*4