
Table 19: Truth Table – Current State Bank n – Command to Bank m
Notes 1–6 apply to all parameters in this table
Current State
CS#
RAS#
CAS#
WE# Command/Action
Notes
Any
H
X
DESELECT (NOP/continue previous operation)
L
H
NO OPERATION (NOP/continue previous operation)
Idle
X
Any command supported to bank m
Row activating,
active, or pre-
charging
L
H
ACTIVE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
L
H
L
WRITE (select column and start WRITE burst)
L
H
L
PRECHARGE
Read (auto pre-
charge disabled)
L
H
ACTIVE (select and activate row)
L
H
L
H
READ (select column and start new READ burst)
L
H
L
WRITE (select column and start WRITE burst)
L
H
L
PRECHARGE
Write (auto pre-
charge disabled)
L
H
ACTIVE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
L
H
L
WRITE (select column and start new WRITE burst)
L
H
L
PRECHARGE
Read (with auto
precharge)
L
H
ACTIVE (select and activate row)
L
H
L
H
READ (select column and start new READ burst)
L
H
L
WRITE (select column and start WRITE burst)
L
H
L
PRECHARGE
Write (with auto
precharge)
L
H
ACTIVE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
L
H
L
WRITE (select column and start new WRITE burst)
L
H
L
PRECHARGE
Notes: 1. This table applies when CKEn - 1 was HIGH, CKEis HIGH and after tXSR has been met (if
the previous state was self refresh), after tXP has been met (if the previous state was power-
down) or after a full initialization (if the previous state was deep power-down).
2. This table describes alternate bank operation, except where noted (for example, the cur-
rent state is for bank n and the commands shown are those supported for issue to bank
m, assuming that bank m is in such a state that the given command is supported). Excep-
tions are covered in the notes below.
3. Current state definitions:
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 and has not yet terminated or been terminated.
Write: A WRITE burst has been initiated and has not yet terminated or been terminated.
enabled state can be broken into two parts: the access period and the precharge period.
For read with auto precharge, the precharge period is defined as if the same burst was
2Gb: x16, x32 Mobile LPDDR SDRAM
Truth Tables
PDF: 09005aef83a73286
2gb_ddr_mobile_sdram_t69m.pdf - Rev. M 11/10 EN
53
Micron Technology, Inc. reserves the right to change products or specifications without notice.
2009 Micron Technology, Inc. All rights reserved.