hyb18m1g16 Qimonda, hyb18m1g16 Datasheet - Page 43

• Manufacturer Part Number: hyb18m1g16
• Description: Drams For Mobile Applications 1-gbit X16 Ddr Mobile-ram Rohs Compliant
• Manufacturer: Qimonda

2.4.9.2
The SELF REFRESH command can be used to retain data in the DDR Mobile-RAM, even if the rest of the system is powered
down. When in the Self Refresh mode, the DDR Mobile-RAM retains data without external clocking. The DDR Mobile-RAM
device has a built-in timer to accommodate Self Refresh operation. The SELF REFRESH command is initiated like an AUTO
REFRESH command except CKE is LOW. Input signals except CKE are “Don’t Care” during Self Refresh. The user may halt
the external clock one clock after Self Refresh entry is registered.
Rev.1.0, 2007-03
10242006-Y557-TZXW
Command
Ba A, Row n = Bank A, Row n
A10 (AP)
Address
DQ
CK
CK
BA0,BA1
A0-A12
CKE
RAS
CAS
Pre All
WE
CK
CK
SELF REFRESH Entry Command
CS
PRE
SELF REFRESH
High-Z
= Don't Care
NOP
t
RP
FIGURE 35
ARF
NOP
t
RFC
43
NOP
Once the command is registered, CKE must be held low to
keep the device in Self Refresh mode. The device executes a
minimum of one AUTO REFRESH command internally once
it enters Self Refresh mode. The clock is internally disabled
during Self Refresh operation to save power. The minimum
time that the device must remain in Self Refresh mode is
The procedure for exiting Self Refresh requires a sequence of
commands. First, the clock must be stable prior to CKE going
back HIGH. Once Self Refresh Exit is registered, a delay of at
least
issued to the device to allow for completion of any internal
refresh in progress.The use of Self Refresh mode introduces
the possibility that an internally timed refresh event can be
missed when CKE is raised for exit from Self Refresh mode.
Upon exit from Self Refresh an extra AUTO REFRESH
command is recommended.
t
XSR
must be satisfied before a valid command can be
ARF
NOP
t
RFC
HY[B/E]18M1G16[0/1]BF
NOP
1-Gbit DDR Mobile-RAM
= Don't Care
FIGURE 34
Row n
Row n
Ba A,
ACT
Auto Refresh
Data Sheet
t
RFC
.