Iei-integration ICE-DB-T6 Manuel d'utilisateur télécharger pdf (Page 61)

Type 6 Carrier Board Design Guide

Page 51

Single-ended Impedance 55 Ohms +/-15%

Spacing between pair to pairs (inter-pair) (s) Min. 20mils

Spacing between differential pairs and high-speed periodic

signals

Min. 20mils

Spacing between differential pairs and low-speed non

periodic signals

Min. 20mils

Length matching between differential pairs (intra-pair) +/- 20mils

Length matching between clock and data pairs (inter-pair) +/- 20mils

Length matching between data pairs (inter-pair) +/- 40mils

Spacing from edge of plane +/- 40mils

Table 3-15: LVDS Impedance Consideration

3.6.4.2 Implement

Many carrier board designs do not need the full range of LVDS performance offered by

COM Express modules. It depends on the flat panel configuration of the COM Express

module, as well as the carrier board design, as to how many LVDS signal pairs are

supported. While the dual channel 24-bit LVDS configuration needs all ten LVDS signal

pairs, a single channel 18-bit LVDS configuration only requires four LVDS signal pairs. In

this case, all unused LVDS signal pairs should be left open on the carrier board. If the

LVDS display interface of the COM Express module is not implemented, all signals

associated with this interface should be left open.

3.7 Audio Codec Interface (AC’97/HDA)

All COM Express module types support Audio Codec '97 (AC'97) and/or High Definition

Audio (HDA) Digital Interface (AC-link) specifically designed for implementing audio and

modem I/O functionality. The corresponding signals can be found on the COM Express

module connector rows A and B.

3.7.1 Signal Description

Table 3-16 shows COM Express audio bus signal, including pin number, signals, I/O,

power plane, terminal resistors, damping resistors and descriptions.

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 128 129

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Iei-integration ICE-DB-T6 Manuel d'utilisateur Page 61