HY[B/E]18L128160B[C/F]-7.5
128-Mbit Mobile-RAM
Functional DescriptionFunction Truth Tables
Table 15
Current State Bank n - Command to Bank n (cont’d)
Current State CS RAS CAS WE Command / Action
Notes
to ,
Read
(Auto-
Precharge
Disabled)
L
L
L
L
L
L
L
L
H
H
L
L
H
L
L
L
H
L
L
L
READ (select column and start new READ burst)
WRITE (select column and start new WRITE burst)
PRECHARGE (truncate READ burst, start precharge)
BURST TERMINATE
to ,
L
to ,
H
H
L
to 11)
to ,
H
H
H
L
Write
(Auto-
Precharge
Disabled)
READ (select column and start READ burst)
WRITE (select column and start WRITE burst)
PRECHARGE (truncate WRITE burst, start precharge)
BURST TERMINATE
to ,
L
to ,
H
H
to ,
H
1) This table applies when CKEn-1 was HIGH and CKEn is HIGH and after tRC has been met (if the previous state was self
refresh).
2) This table is bank-specific, except where noted, i.e., 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:
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.
4) The following states must not be interrupted by a command issued to the same bank. DESELECT 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 bank are determined by its current state and according to Table 16.
Precharging:Starts with registration of a PRECHARGE command and ends when tRP is met. Once tRP is met, the bank
is in the “idle” state.
Row Activating:Starts with registration of an ACTIVE command and ends when tRCD is met. Once tRCD is met, the bank
is in the “row active” state.
Read with AP
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 is in the idle state.
Write with AP
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 is in the idle state.
5) The following states must not be interrupted by any executable command; DESELECT or NOP commands must be applied
on each positive clock edge during these states.
Refreshing:Starts with registration of an AUTO REFRESH command and ends when tRC is met. Once tRC is met, the
SDRAM is in the “all banks idle” state.
Accessing Mode
Register:Starts with registration of a MODE REGISTER SET command and ends when tMRD has been met. Once
tMRD is met, the SDRAM is in the “all banks idle” state.
Precharging All:Starts with registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP is met, all
banks are in the idle state.
6) All states and sequences not shown are illegal or reserved.
7) Not bank-specific; requires that all banks are idle and no bursts are in progress.
8) Same as NOP command in that state.
9) READs or WRITEs listed in the Command/Action column include READs or WRITEs with Auto Precharge enabled and
READs or WRITEs with Auto Precharge disabled.
10) May or may not be bank-specific; if multiple banks are to be precharged, each must be in a valid state for precharging.
11) Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE burst, regardless of bank.
Data Sheet
42
Rev. 1.71, 2007-01
05282004-NZNK-8T0D
QIMONDA [ QIMONDA AG ]
