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128Mbx16x32Mobile_2.fm - Rev. M 1/09 EN
45
2001 Micron Technology, Inc. All rights reserved.
128Mb: x16, x32 Mobile SDRAM
READs
Notes:
after tXSR has been met (if the previous state was self refresh).
2. This table is bank-specific, except where noted; that is, the current state is for a specific
bank and the commands shown are those allowed to be issued to that bank when in that
state. Exceptions are covered in the notes below.
3. Current state definitions:
4. The following states must not be interrupted by a command issued to the same bank. COM-
MAND INHIBIT or NOP commands or allowable commands to the other bank should be
issued on any clock edge occurring during these states. Allowable commands to the other
Table 10:
Truth Table – Current State Bank n, Command to Bank n
Notes
1–6 apply to entire table; notes appear below table
Current
State
CS#
RAS# CAS# WE# Command (Action)
Notes
Any
H
XXX
COMMAND INHIBIT (NOP/Continue previous operation)
L
HHH
NO OPERATION (NOP/Continue previous operation)
Idle
L
H
ACTIVE (Select and activate row)
LLL
H
AUTO REFRESH
LLLL
LOAD MODE REGISTER
LL
H
L
PRECHARGE
Row active
LH
READ (Select column and start READ burst)
LH
L
WRITE (Select column and start WRITE burst)
LL
H
L
PRECHARGE (Deactivate row in bank or banks)
Read (auto
precharge
disabled)
LH
READ (Select column and start new READ burst)
LH
L
WRITE (Select column and start WRITE burst)
LL
H
L
PRECHARGE (Truncate READ burst, start PRECHARGE)
LH
H
L
BURST TERMINATE
Write (auto
precharge
disabled)
LH
READ (Select column and start READ burst)
LH
L
WRITE (Select column and start new WRITE burst)
LL
H
L
PRECHARGE (Truncate WRITE burst, start PRECHARGE)
LH
H
L
BURST TERMINATE
Idle: The bank has been precharged, and tRP has been met.
Row active: A row in the bank has been activated, and tRCD has been met. No data
bursts/accesses and no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not
yet terminated or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has
not yet terminated or been terminated.
Precharging: Starts with registration of a PRECHARGE command and ends when
tRP is met. After tRP is met, the bank will be in the idle state.
Row activating: Starts with registration of an ACTIVE command and ends when tRCD
is met. After tRCD is met, the bank will be in the row active state.
Read w/auto
precharge enabled:
Starts with registration of a READ command with auto precharge
enabled and ends when tRP has been met. AFter tRP is met, the bank
will be in the idle state.
Write w/auto
precharge enabled:
Starts with registration of a WRITE command with auto precharge
enabled and ends when tRP has been met. After tRP is met, the bank
will be in the idle state.