HYB25L512160AC Datasheet, PDF (35/50 Pages) Infineon Technologies AG – 512MBit Mobile-RAM

HYB25L512160AC–7.5
512MBit Mobile-RAM
Functional Description
WRITE to PRECHARGE
A WRITE burst may be followed by, or truncated with a PRECHARGE command to the same bank (provided that
Auto Precharge was not activated), as shown in Figure 37.
The PRECHARGE command should be issued t_WR after the clock edge at which the last desired data element of
the WRITE burst was registered. Additionally, when truncating a WRITE burst, DQM must be pulled to mask input
data presented during t_WR prior to the PRECHARGE command. Following the PRE-CHARGE command, a
subsequent ACTIVE command to the same bank cannot be issued until t_RP is met.
In the case of a WRITE 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 WRITE burst with Auto Precharge
enabled. 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.
CLK
Command NOP
Address
A10
(AP)
DQM
DQ
WRITE
Ba A,
Col n
Dis AP
NOP
NOP
DI n
DI n+1
DI n+2
t_WR
NOP
PRE
t_RP
NOP
Ba A
Pre All
AP
Pre Bank A
ACT
Ba A,
Row a
Ba A, Col n = bank A, column n
DI n = Data In to column n
AP = Auto Precharge
Dis AP = Disable Auto Precharge
= Don't Care
Burst Length = 4 in the case shown.
3 subsequent elements of Data In are provided in the programmed order following DI n.
DI n+3 is masked due to DQM pulled HIGH during t_WR period prior to PRECHARGE command.
Figure 37 WRITE to PRECHARGE Timing
3.4.7
.
BURST TERMINATE
CLK
CKE
CS
RAS
CAS
WE
A0-A12
BA0,BA1
(High)
= Don't Care
Figure 38 BURST TERMINATE Command
The BURST TERMINATE command is used to
truncate READ or WRITE bursts (with Auto
Precharge disabled). The most recently registered
READ or WRITE command prior to the BURST
TERMINATE command will be truncated, as shown in
Figure 21 and Figure 33, respectively
Data Sheet
35
Rev. 1.3, 2004-04
10212003-BSPE-77OL