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Carrier Board Design Guide for SOM-9X35 Module
39
Metrics
Information/Design Guidance
Length match
Differential pair trace mismatch
<5mil
Pair to pair trace mismatch
<27mil
Data-to-clock slew
<55mil
Maximum trace length
4000 mil
Spacing
Spacing to all other signals
4 x line width
Spacing data lane-to-lane
3 x line width
Table 14: LVDS layout guidelines
The carrier board LVDS trace length and mismatch calculations should take into account the SOM-9X35 module
LVDS bus from the SOM-9X35 module.
Net Name
Trace
Length
(mil)
Length
Spec (mil)
Length
Mismatch
(mil)
Length
Mismatch
Spec (mil)
Total
Delay
(Trace +
Via) (ps)
Delay
Mismatch
(ps)
Delay
Mismatch
Spec (ps)
Notes
LVDS_TX_D0P
1504.27
4000
-0.55
6.75
252.61
0.14
1
Inter-pair
LVDS_TX_D0N
1504.82
252.47
LVDS_TX_D0P
-25.91
29.74
-0.63
5
Pair-to-Pair
LVDS_TX_D0N
-27.95
-1.00
LVDS_TX_D1P
1536.50
4000
4.44
6.75
253.71
0.20
1
Inter-pair
LVDS_TX_D1N
1532.06
253.51
LVDS_TX_D1P
6.32
29.74
0.47
5
Pair-to-Pair
LVDS_TX_D1N
-0.71
0.04
LVDS_TX_CKP
1530.18
4000
-2.59
6.75
253.24
-0.23
1
Inter-pair
LVDS_TX_CKN
1532.77
253.47
LVDS_TX_D2P
1513.79
4000
-1.55
6.75
252.26
-0.28
1
Inter-pair
LVDS_TX_D2N
1515.35
252.54
LVDS_TX_D2P
-16.38
29.74
-0.97
5
Pair-to-Pair
LVDS_TX_D2N
-17.42
-0.92
LVDS_TX_D3P
1530.94
4000
5.46
6.75
253.08
0.46
1
Inter-pair
LVDS_TX_D3N
1525.48
252.62
LVDS_TX_D3P
0.76
29.74
-0.15
5
Pair-to-Pair
LVDS_TX_D3N
-7.29
-0.85
Table 15: SOM-9X35 LVDS trace & via delay