mt46h32m16lf Micron Semiconductor Products, mt46h32m16lf Datasheet - Page 33

• Manufacturer Part Number: mt46h32m16lf
• Description: 512mb X16, X32 Mobile Ddr Sdram
• Manufacturer: Micron Semiconductor Products

SELF REFRESH
DEEP POWER-DOWN
Figure 5:
PDF: 09005aef82ce3074/Source: 09005aef82ce20c9
ddr_mobile_sdram_cmd_op_timing_dia_fr3.08__3.fm - Rev. D 05/08 EN
DEEP POWER-DOWN Command
The SELF REFRESH command can be used to retain data in the Mobile DDR SDRAM,
even if the rest of the system is powered down. When in the self refresh mode, the Mobile
DDR SDRAM retains data without external clocking. The SELF REFRESH command is
initiated like an AUTO REFRESH command, except that CKE is disabled (LOW). All
command and address input signals except CKE are “Don’t Care” during SELF REFRESH.
See Figure 48 on page 77 for details on entering and exiting self refresh mode.
During SELF REFRESH, the device is refreshed as identified in the extended mode
register (see “Partial-Array Self Refresh (PASR)” on page 45). An internal temperature
sensor will adjust the refresh rate to optimize device power consumption while ensuring
data integrity (see “Temperature-Compensated Self Refresh (TCSR)” on page 45).
The procedure for exiting SELF REFRESH requires a sequence of commands. First, CK
must be stable prior to CKE going back HIGH. Once CKE is HIGH, the Mobile DDR
SDRAM must have NOP commands issued for
During SELF REFRESH operation, refresh intervals are scheduled internally, and may
vary. These refresh intervals may be different then the specified
reason, the SELF REFRESH command must not be used as a substitute for the AUTO
REFRESH command.
The DEEP POWER-DOWN (DPD) command is used to enter DPD operating mode,
which achieves maximum power reduction by eliminating the power of the memory
array. Data will not be retained when the device enters DPD mode. The DPD command
is the same as a BURST TERMINATE command with CKE LOW.
BA0, BA1
Address
RAS#
CAS#
WE#
CK#
CKE
CS#
CK
Don’t Care
33
Micron Technology, Inc., reserves the right to change products or specifications without notice.
t
XSR time.
Mobile DDR SDRAM
©2007 Micron Technology, Inc. All rights reserved
t
REFI time. For this
Commands