Data Sheet
HY[B/E]18M1G16[0/1]BF
1-Gbit DDR Mobile-RAM
2.4.7.2
WRITE to PRECHARGE
Data for any WRITE burst may be followed by a subsequent PRECHARGE command. To follow a WRITE without truncating
the WRITE burst, tWR should be met as shown in Figure 30.
FIGURE 30
Non-Interrupting WRITE to PRECHARGE (max. tDQSS
)
CK
CK
Command
WRITE
NOP
NOP
NOP
NOP
tWR
PRE
BA a
Address
BA,Col b
(or all)
tDQSSmax
DQS
DQ
Di b
DM
DI b = Data In to column b .
3 subsequent elements of Data In are applied in the programmed order following DI b.
A non-interrupted burst of 4 is shown.
= Don't Care
t
WR is referenced from the positive clock edge after the last Data In pair.
A10 is LOW with the WRITE command (Auto Precharge is disabled)
Data for any WRITE burst may be truncated by a subsequent PRECHARGE command, as shown in Figure 31. Note that only
the data-in pairs that are registered prior to the tWR period are written to the internal array, and any subsequent data in should
be masked with DM. Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until
t
RP is met.
In the case of a WRITE burst being executed to completion, a PRECHARGE command issued at the optimum time (as
described above) provides the same operation that would result from the same burst with Auto Precharge. The disadvantage
of the PRECHARGE command is that it requires that the command and address busses be available at the appropriate time
to issue the command. The advantage of the PRECHARGE command is that it can be used to truncate bursts.
Rev.1.0, 2007-03
39
10242006-Y557-TZXW
QIMONDA [ QIMONDA AG ]
