HY[B/E]18L256160B[C/F]X-7.5
256-Mbit Mobile-RAM
Functional Description
2.5
Function Truth Tables
Table 14
Current State Bank n - Command to Bank n
Current State
CS RAS CAS WE Command / Action
Notes
1)2)3)4)5)6)
Any
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
H
L
X
H
H
L
X
H
H
H
L
DESELECT (NOP / continue previous operation)
1) to 6)
NO OPERATION (NOP / continue previous operation)
ACTIVE (select and activate row)
1) to 6)
Idle
1) to 7)
L
AUTO REFRESH
1) to 7)
L
L
MODE REGISTER SET
1) to 6), 8)
1) to 6), 9)
1) to 6), 9)
1) to 6), 10)
1) to 6), 9)
1) to 6), 9)
1) to 6), 10)
1) to 6), 11)
1) to 6), 9)
1) to 6), 9)
1) to 6), 10)
1) to 6), 11)
L
H
L
L
PRECHARGE
Row Active
H
H
L
H
L
READ (select column and start READ burst)
WRITE (select column and start WRITE burst)
PRECHARGE (deactivate row in bank or banks)
READ (select column and start new READ burst)
WRITE (select column and start new WRITE burst)
PRECHARGE (truncate READ burst, start precharge)
BURST TERMINATE
L
H
L
L
Read
(Auto-
Precharge
Disabled)
H
H
L
H
L
L
H
H
L
L
H
H
H
L
L
Write
(Auto-
Precharge
Disabled)
H
L
READ (select column and start READ burst)
WRITE (select column and start WRITE burst)
PRECHARGE (truncate WRITE burst, start precharge)
BURST TERMINATE
L
H
H
L
H
L
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:
Write:
A READ burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been
terminated.
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 15.
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.
Data Sheet
37
Rev. 1.11, 2007-01
07142005-CR47-RB2E
QIMONDA [ QIMONDA AG ]
