HY[B/E]18L256160B[C/F]X-7.5
256-Mbit Mobile-RAM
Functional Description
2.4.6.5
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. This is shown in Figure 34.
The PRECHARGE command should be issued tWR 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 tWR prior to the PRECHARGE command. Following the PRE-CHARGE command, a
subsequent ACTIVE command to the same bank cannot be issued until tRP 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.
#,+
T72
T20
./0
72)4%
./0
./0
./0
02%
./0
!#4
#OMMAN
RESS
"A !ꢏ
#OL N
"A !ꢏ
!
"A !
2OW A
0RE !LL
!0
!ꢀꢂ
ꢌ!0ꢍ
$IS !0
$) N
0RE "ANK !
$1-
$1
$) Nꢔꢀ
$) Nꢔꢁ
"A !ꢏ #OL N ꢒ BANK !ꢏ COLUMN N
$) N ꢒ $ATA )N TO COLUMN N
!0 ꢒ !UTO 0RECHARGE
$IS !0 ꢒ $ISABLE !UTO 0RECHARGE
ꢒ $ONgT #ARE
"URST ,ENGTH ꢒ ꢈ IN THE CASE SHOWNꢐ
ꢆ SUBSEQUENT ELEMENTS OF $ATA )N ARE PROVI E IN THE PROGRAMME OR ER FOLLOWING $) Nꢐ
$) Nꢔꢆ IS MASKE UE TO $1- PULLE ()'( URING T72 PERIO PRIOR TO 02%#(!2'% COMMAN ꢐ
Figure 34 WRITE to PRECHARGE Timing
2.4.7
BURST TERMINATE
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 18 and
Figure 30, respectively.
#,+
#+%
#3
ꢌ(IGHꢍ
The BURST TERMINATE command is not allowed for
truncation of READ or WRITE bursts with Auto
Precharge enabled.
2!3
#!3
7%
!ꢂꢎ!ꢀꢁ
"!ꢂꢏ"!ꢀ
ꢒ $ONgT #ARE
Figure 35 BURST TERMINATE Command
Data Sheet
30
Rev. 1.11, 2007-01
07142005-CR47-RB2E