Data Sheet.
HY[B/E]18L512160BF-7.5
512-Mbit Mobile-RAM
TABLE 14
Timing Parameters for PRECHARGE
Parameter
Symbol
- 7.5
Units
Notes
min.
max.
1)
1)
1)
ACTIVE to PRECHARGE command period
WRITE recovery time
PRECHARGE command period
tRAS
tWR
tRP
45
14
19
100k
—
—
ns
ns
ns
1) These parameters account for the number of clock cycles and depend on the operating frequency as follows:no. of clock cycles = specified
delay / clock period; round up to next integer.
2.4.8.2
CONCURRENT AUTO PRECHARGE
A READ or WRITE burst with Auto Precharge enabled can be interrupted by a subsequent READ or WRITE command issued
to a different bank.
Figure 37 shows a READ with Auto Precharge to bank n, interrupted by a READ (with or without Auto Precharge) to bank m.
The READ to bank m will interrupt the READ to bank n, CAS latency later. The precharge to bank n will begin when the READ
to bank m is registered.
Figure 38 shows a READ with Auto Precharge to bank n, interrupted by a WRITE (with or without Auto Precharge) to bank m.
The precharge to bank n will begin when the WRITE to bank m is registered. DQM should be pulled HIGH two clock cycles
prior to the WRITE to prevent bus contention.
Figure 39 shows a WRITE with Auto Precharge to bank n, interrupted by a READ (with or without Auto Precharge) to bank m.
The precharge to bank n will begin tWR after the new command to bank m is registered. The last valid data-in to bank n is one
clock cycle prior to the READ to bank m.
Figure 40 shows a WRITE with Auto Precharge to bank n, interrupted by a WRITE (with or without Auto Precharge) to bank
m. The precharge to bank n will begin tWR after the WRITE to bank m is registered. The last valid data-in to bank n is one clock
cycle prior to the WRITE to bank m.
FIGURE 37
READ with Auto Precharge Interrupted by READ
#,+
./0
2$ꢀ!0
./0
2%!$
./0
./0
./0
./0
#OMMAND
!DDRESS
"ANK N
#OL B
"ANK M
#OL X
#,ꢁꢃ
T20 ꢇBANK Nꢈ
$/ Bꢅꢆ
$/ B
$/ X
$/ Xꢅꢆ
$/ Xꢅꢃ
$1
ꢁ $ONgT #ARE
2$ꢀ!0 ꢁ 2EAD WITH !UTO 0RECHARGEꢂ 2%!$ ꢁ 2EAD WITH OR WITHOUT !UTO 0RECHARGE
#, ꢁ ꢃ AND "URST ,ENGTH ꢁ ꢄ IN THE CASE SHOWN
2EAD WITH !UTO 0RECHARGE TO BANK N IS INTERRUPTED BY SUBSEQUENT 2EAD TO BANK M
Rev. 1.22, 2006-12
01132005-06IU-IGVM
37
QIMONDA [ QIMONDA AG ]
