mt47h128m16hg-3-it Micron Semiconductor Products, mt47h128m16hg-3-it Datasheet - Page 60

• Manufacturer Part Number: mt47h128m16hg-3-it
• Description: 2gb X4, X8, X16 Ddr2 Sdram
• Manufacturer: Micron Semiconductor Products

PRECHARGE Command
PRECHARGE Operation
Figure 44:
PDF: 09005aef824f87b6/Source: 09005aef824f1182
2gb_ddr2.fm - Rev. A 9/06 EN
PRECHARGE Command
Note:
The PRECHARGE command, illustrated in Figure 44, is used to deactivate the open row
in a particular bank or the open row in all banks. The bank(s) will be available for a
subsequent row activation a specified time (
issued, except in the case of concurrent auto precharge, where a READ or WRITE
command to a different bank is allowed as long as it does not interrupt the data transfer
in the current bank and does not violate any other timing parameters. Once a bank has
been precharged, it is in the idle state and must be activated prior to any READ or WRITE
commands being issued to that bank. A PRECHARGE command is allowed if there is no
open row in that bank (idle state) or if the previously open row is already in the process
of precharging. However, the precharge period will be determined by the last
PRECHARGE command issued to the bank.
Input A10 determines whether one or all banks are to be precharged, and in the case
where only one bank is to be precharged, inputs BA2–BA0 select the bank. Otherwise
BA2–BA0 are treated as “Don’t Care.”
When all banks are to be precharged, inputs BA2–BA0 are treated as “Don’t Care.” Once a
bank has been precharged, it is in the idle state and must be activated prior to any READ
or WRITE commands being issued to that bank.
PRECHARGE (ALL) command is issued, regardless of the number of banks already open
or closed. If a single-bank PRECHARGE command is issued,
(MIN) applies to all 8-bank DDR2 devices.
BA2, BA0, BA1
BA = bank address (if A10 is LOW; otherwise “Don’t Care”).
ADDRESS
CAS#
RAS#
WE#
A10
CKE
CK#
CS#
CK
HIGH
ALL BANKS
ONE BANK
DON’T CARE
BA
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Micron Technology, Inc., reserves the right to change products or specifications without notice.
t
RP) after the PRECHARGE command is
2Gb: x4, x8, x16 DDR2 SDRAM
t
RPA timing applies when the
PRECHARGE Command
t
RP timing applies.
©2006 Micron Technology, Inc. All rights reserved.
t
RPA