
not be issued until tRP is met. However, part of the row precharge time is hidden during
the access of the last data elements.
for BL = 8. The delay from READ-to-PRECHARGE period to the same bank is AL + BL/
2 - 2CK + MAX (tRTP/tCK or 2 × CK) where MAX means the larger of the two.
Figure 50: READ-to-PRECHARGE – BL = 4
CK
CK#
T0
T1
T2
Don’t Care
Transitioning Data
T3
T4
T5
T6
T7
Address
Bank a
≥t
RAS (MIN)
≥t
RTP (MIN)
≥t
RP (MIN)
AL + BL/2 - 2CK + MAX (tRTP/tCK or 2CK)
Command
READ
NOP
PRE
ACT
NOP
4-bit
prefetch
DQ
DO
A10
Valid
CL = 3
AL = 1
DQS, DQS#
≥t
RC (MIN)
Notes: 1. RL = 4 (AL = 1, CL = 3); BL = 4.
2. tRTP
≥ 2 clocks.
3. Shown with nominal tAC, tDQSCK, and tDQSQ.
Figure 51: READ-to-PRECHARGE – BL = 8
CK
CK#
T0
T1
T2
Don’t Care
Transitioning Data
T3
T4
T5
T6
T7
T8
CL = 3
AL = 1
DQS, DQS#
First 4-bit
prefetch
Second 4-bit
prefetch
≥
tRTP (MIN)
≥
tRP (MIN)
Address
Bank a
≥
tRC (MIN)
≥
tRAS (MIN)
A10
Valid
AL + BL/2 - 2CK + MAX (tRTP/tCK or 2CK)
DQ
DO
Command
READ
NOP
ACT
PRE
Notes: 1. RL = 4 (AL = 1, CL = 3); BL = 8.
2. tRTP
≥ 2 clocks.
3. Shown with nominal tAC, tDQSCK, and tDQSQ.
1Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
PDF: 09005aef82b91d01
1GbDDR2_1_55V.PDF Rev. A 5/09 EN
93
Micron Technology, Inc. reserves the right to change products or specifications without notice.
2009 Micron Technology, Inc. All rights reserved.