
Figure 79: Method for Calculating tLZ and tHZ
tHZ (DQS), tHZ (DQ)
tHZ (DQS), tHZ (DQ) end point = 2 × T1 - T2
VOH - xmV
VTT - xmV
VOL + xmV
VTT + xmV
VOH - 2xmV
VTT - 2xmV
VOL + 2xmV
VTT + 2xmV
tLZ (DQS), tLZ (DQ)
tLZ (DQS), tLZ (DQ) begin point = 2 × T1 - T2
T1
T2
Notes: 1. Within a burst, the rising strobe edge is not necessarily fixed at tDQSCK (MIN) or tDQSCK
(MAX). Instead, the rising strobe edge can vary between tDQSCK (MIN) and tDQSCK (MAX).
2. The DQS high pulse width is defined by tQSH, and the DQS low pulse width is defined by
tQSL. Likewise, tLZ (DQS) MIN and tHZ (DQS) MIN are not tied to tDQSCK (MIN) (early
strobe case) and tLZ (DQS) MAX and tHZ (DQS) MAX are not tied to tDQSCK (MAX) (late
strobe case); however, they tend to track one another.
3. The minimum pulse width of the READ preamble is defined by tRPRE (MIN). The mini-
mum pulse width of the READ postamble is defined by tRPST (MIN).
Figure 80: tRPRE Timing
tRPRE
DQS - DQS#
DQS
DQS#
T1
tRPRE begins
T2
tRPRE ends
CK
CK#
VTT
Resulting differential
signal relevant for
tRPRE specification
tC
tA
tB
tD
Single-ended signal provided
as background information
0V
Single-ended signal provided
as background information
VTT
2Gb: x4, x8, x16 DDR3 SDRAM
PDF: 09005aef826aaadc
2Gb_DDR3_SDRAM.pdf – Rev. K 04/10 EN
164
Micron Technology, Inc. reserves the right to change products or specifications without notice.
2006 Micron Technology, Inc. All rights reserved.