MT48H8M16LF Datasheet, PDF (37/64 Pages) Micron Technology – Synchronous DRAM

128Mb: x16 Mobile SDRAM
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Table 9: Truth Table 4 – Current State Bank n, Command to Bank m
Notes: 1-6; notes appear below and on next page.
Current State
Any
Idle
Row
Activating,
Active, or
Precharging
Read
(Auto
Precharge
Disabled)
Write
(Auto
Precharge
Disabled)
Read
(With Auto
Precharge)
Write
(With Auto
Precharge)
CS# RAS# CAS# WE# Command (Action)
Notes
H
X
X
X COMMAND INHIBIT (NOP/Continue previous operation)
L
H
H
H NO OPERATION (NOP/Continue previous operation)
X
X
X
X Any command allowed to bank m
L
L
H
H ACTIVE (Select and activate row)
L
H
L
H READ (Select column and start READ burst)
7
L
H
L
L WRITE (Select column and start WRITE burst)
7
L
L
H
L PRECHARGE
L
L
H
H ACTIVE (Select and activate row)
L
H
L
H READ (Select column and start new READ burst)
7, 10
L
H
L
L WRITE (Select column and start WRITE burst)
7, 11
L
L
H
L PRECHARGE
9
L
L
H
H ACTIVE (Select and activate row)
L
H
L
H READ (Select column and start READ burst)
7, 12
L
H
L
L WRITE (Select column and start new WRITE burst)
7, 13
L
L
H
L PRECHARGE
9
L
L
H
H ACTIVE (Select and activate row)
L
H
L
H READ (Select column and start new READ burst)
7, 8, 14
L
H
L
L WRITE (Select column and start WRITE burst)
7, 8, 15
L
L
H
L PRECHARGE
9
L
L
H
H ACTIVE (Select and activate row)
L
H
L
H READ (Select column and start READ burst)
7, 8, 16
L
H
L
L WRITE (Select column and start new WRITE burst)
7, 8, 17
L
L
H
L PRECHARGE
9
Notes: 1. This table applies when CKE_n-1 was HIGH and CKE_n is HIGH (see Truth Table 2) and after
t_{XSR has been met (if the previous state was self refresh).}
2. This table describes alternate bank operation, except where noted; i.e., the current state is
for bank n and the commands shown are those allowed to be issued to bank m (assuming
that bank m is in such a state that the given command is allowable). Exceptions are cov-
ered 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, 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.
Read w/Auto Precharge Enabled: Starts with registration of a READ command with auto
precharge enabled, and ends when ^tRP has been met. Once ^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. Once ^tRP is met, the
bank will be in the idle state.
4. AUTO REFRESH, SELF REFRESH, and LOAD MODE REGISTER commands may only be issued
when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank
represented by the current state only.
6. All states and sequences not shown are illegal or reserved.
PDF: 09005aef80c97087/Source: 09005aef80c97015
MT48H8M16_2.fm - Rev. E 3/05 EN
37
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