256Mb: x4, x8, x16 SDRAM
AUTO REFRESH Operation
Figure 52: Auto Refresh Mode
T0
T1
T2
Tn + 1
CL
To + 1
( (
) )
( (
) )
t
CLK
CKE
t
t
( (
( (
CK
CH
) )
) )
( (
) )
( (
) )
t
t
CKS
CKH
t
t
CMS
CMH
( (
) )
( (
) )
AUTO
REFRESH
AUTO
REFRESH
Command
DQM
PRECHARGE
NOP
NOP
NOP
NOP
NOP
ACTIVE
( (
( (
) )
) )
( (
) )
( (
) )
( (
( (
) )
) )
( (
) )
( (
) )
( (
) )
( (
) )
Row
Row
Address
A10
( (
) )
( (
) )
( (
) )
( (
) )
All banks
Single bank
t
t
AH
AS
( (
) )
( (
) )
BA0, BA1
DQ
Bank(s)
Bank
( (
( (
) )
) )
High-Z
( (
) )
( (
) )
t
t
t
RFC
RP
RFC
Precharge all
active banks
Don’t Care
1. Back-to-back AUTO REFRESH commands are not required.
Note:
PDF: 09005aef8091e6d1
256Mb_sdr.pdf - Rev. R 10/12 EN
Micron Technology, Inc. reserves the right to change products or specifications without notice.
80
© 1999 Micron Technology, Inc. All rights reserved.
MICRON [ MICRON TECHNOLOGY ]
