HYB39S13620TQ- Datasheet, PDF (18/70 Pages) Siemens Semiconductor Group – Special Mode Registers Two color registers Burst Read with Single Write Operation

HYB 39S16320TQ-6/-7/-8
Detailed Description of WRITE COMMANDS (WR, Masked Writes, Block Write)
Write Command (WR)
The following pages illustrate the Write operations for various cases.
Summary Write Commands
Mnemonic CKE CS RAS CAS WE DSF DQM BA A8 Address
Lines
WR
H
L
H
L
L
L
0
BA L
Column
WRA
H
L
H
L
L
L
0
BA H
Column
BW
H
L
H
L
L
H
0
BA L
Column
BWA
H
L
H
L
L
H
0
BA H
Column
Notes
1. Input data at DQ pins at Block Write command is registed as a column mask for that block of
columns
2. Explanation of Mnemonics:
WR: Write Command
WRA: Write Command with Auto Precharge
BW: Block Write
BWA: Block Write with Auto Precharge
BA: Bank Select
Write bursts are initiated with a Write command. The starting column and bank address is provided
with the Write command, normal or Block Write is selected, and Auto Precharge is either enabled
or disabled for that access. If Auto Precharge is enabled, the row being accessed is precharged
automatically at the completion of the burst.
During Write bursts, the first valid data-in element will be registered coincident with the Write
command. Sub-sequent data elements will be registered on successive positive clock edge. Upon
completion of a fixed-length burst, assuming no other commands have been initiated, the DQs will
remain High-Z, and any additional data will be ignored. A full-page burst will continue until
terminated (at the end of the page, it will wrap to column 0 and continue).
A fixed-length Write burst may be followed by, or truncated with a subsequent Write burst or Block
Write command (provided that Auto Precharge was not activated) and a full page Write burst can
be truncated with a subsequent Write burst or Block Write command. The new Write or Block Write
command can be issued on any clock following the previous Write command, and the data provided
coincident with the new command applies to the new command. To truncate a Block Write, the t_BWC
parameter has to be met.
A fixed-length Write burst may be followed by, or truncated with a subsequent Read burst (provided
that Auto Precharge was not activated) and a full-page Write burst can be truncated with a
subsequent Read burst. Once the Read command is registered, the data inputs will be ignored, and
writes will not be executed.
Semiconductor Group
18
1998-10-01