1GB-AUTO-AS4C128M8D3 Datasheet, PDF (59/84 Pages) Alliance Semiconductor Corporation – Fully synchronous operation

1Gb Auto-AS4C128M8D3
- Address / Command Setup, Hold and Derating
For all input signals the total tIS (setup time) and tIH (hold time) required is calculated by adding the data sheet
tIS(base) and tIH(base) and tIH(base) value to the delta tIS and delta tIH derating value respectively.
Example: tIS (total setup time) = tIS(base) + delta tIS.
Setup (tIS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of Vref(dc) and
the first crossing of VIH(ac)min. Setup (tIS) nominal slew rate for a falling signal is defined as the slew rate between
the last crossing of Vref(dc) and the first crossing of VIL(ac)max. If the actual signal is always earlier than the
nominal slew rate line between shaded ‘Vref(dc) to ac region’, use nominal slew rate for derating value. If the actual
signal is later than the nominal slew rate line anywhere between shaded ‘Vref(dc) to ac region’, the slew rate of the
tangent line to the actual signal from the ac level to dc level is used for derating value.
Hold (tIH) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VIL(dc)max
and the first crossing of Vref(dc). Hold (tIH) nominal slew rate for a falling signal is defined as the slew rate between
the last crossing of VIH(dc)min and the first crossing of Vref(dc). If the actual signal is always later than the nominal
slew rate line between shaded ‘dc to Vref(dc) region’, use nominal slew rate for derating value. If the actual signal is
earlier than the nominal slew rate line anywhere between shaded ‘dc to Vref(dc) region’, the slew rate of a tangent
line to the actual signal from the dc level to Vref(dc) level is used for derating value. For a valid transition the input
signal has to remain above/below VIH/IL(ac) for some time tVAC. Although for slow slew rates the total setup time
might be negative (i.e. a valid input signal will not have reached VIH/IL(ac) at the time of the rising clock transition) a
valid input signal is still required to complete the transition and reach VIH/IL(ac).
Table 40. ADD/CMD Setup and Hold Base - Values for 1V/ns
Symbol
Reference
-12BAN
Unit
t_IS(base) AC175
V_IH/L(ac)
45
ps
t_IS(base) AC150
V_IH/L(ac)
170
ps
t_IH(base) DC100
V_IH/L(dc)
120
ps
NOTE 1: (ac/dc referenced for 1V/ns Address/Command slew rate and 2 V/ns differential CK-CK# slew rate)
NOTE 2: The tIS(base) AC150 specifications are adjusted from the tIS(base) AC175 specification by adding an additional 100ps
of derating to accommodate for the lower alternate threshold of 150 mV and another 25 ps to account for the earlier reference
point [(175 mv - 150 mV) / 1 V/ns].
Table 41. Derating values DDR3-1333/1600 tIS/tIH – (AC175)
CMD
/AD
D
Slew
Rate
V/ns
t_IS, t_IH derating in [ps] AC/DC based AC175 Threshold -> V_IH(ac)=V_REF(dc)+175mV, V_IL(ac)=V_REF(dc)-175mV
CK, CK# Differential Slew Rate
4.0 V/ns
tIS
tIH
3.0 V/ns
tIS
tIH
2.0 V/ns
tIS
tIH
1.8 V/ns
tIS
tIH
1.6 V/ns
tIS
tIH
1.4 V/ns
tIS
tIH
1.2 V/ns
tIS
tIH
1.0 V/ns
tIS
tIH
2.0 88
50
88
50
88
50
96
58 104 66 112 74 120 84 128 100
1.5 59
34
59
34
59
34
67
42
75
50
83
58
91
68
99
84
1.0
0
0
0
0
0
0
8
8
16 16 24 24 32 34 40 50
0.9 -2
-4
-2
-4
-2
-4
6
4
14 12 22 20 30 30 38 46
0.8 -6 -10
-6 -10 -6
-10
2
-2
10
6
18 14 26 24 34 40
0.7 -11 -16 -11 -16 -11 -16 -3
-8
5
0
13
8
21 18 29 34
0.6 -17 -26 -17 -26 -17 -26 -9 -18 -1
-10
7
-2
15
8
23 24
0.5 -35 -40 -35 -40 -35 -40 -27 -32 -19 -24 -11 -16 -2
-6
5
10
0.4 -62 -60 -62 -60 -62 -60 -54 -52 -46 -44 -38 -36 -30 -26 -22 -10
Table 42. Derating values DDR3-1333/1600 tIS/tIH – (AC150)
t_IS, t_IH derating in [ps] AC/DC based Alternate AC150 Threshold -> V_IH(ac)=V_REF(dc)+150mV, V_IL(ac)=V_REF(dc)-150mV
CK, CK# Differential Slew Rate
CMD 2.0
/AD _1.5
D
Slew
1.0
Rate ^0.9
V/ns ^0.8
0.7
4.0 V/ns
tIS
tIH
75
50
50
34
0
0
0
-4
0
-10
0
-16
3.0 V/ns
tIS
tIH
75 50
50 34
0
0
0
-4
0
-10
0
-16
2.0 V/ns
tIS
tIH
75
50
50
34
0
0
0
-4
0
-10
0
-16
1.8 V/ns
tIS
tIH
83
58
58
42
8
8
8
4
8
-2
8
-8
1.6 V/ns
tIS
tIH
91 66
66 50
16 16
16 12
16
6
16
0
1.4 V/ns
tIS
tIH
99 74
74 58
24 24
24 20
24 14
24
8
1.2 V/ns
tIS
tIH
107 84
82 68
32 34
32 30
32 24
32 18
1.0 V/ns
tIS
tIH
115 100
90 84
40 50
40 46
40 40
40 34
0.6 -1 -26 -1 -26 -1 -26
7
-18 15 -10 23
-2
31
8
39 24
0.5 -10 -40 -10 -40 -10 -40 -2 -32
6
-24 14 -16 22
-6
30
10
0.4 -25 -60 -25 -60 -25 -60 -17 -52 -9
-44 -1 -36
7
-26 15 -10
- Data Setup, Hold, and Slew Rate De-rating
For all input signals the total tDS (setup time) and tDH (hold time) required is calculated by adding the data sheet
tDS(base) and tDH(base) value to the ΔtDS and ΔtDH derating value respectively.
Confidential
-59-
Rev.1.0 May 2015