cExpress-TL User’s Guide
PICMG COM.0 R3.0
Page 24
Copyright © 2021 ADLINK Technology, Inc.
4.2.
Signal Terminology Descriptions
Meaning of the terms used for signal description tables
Term
Description
I
Input to the module
O
Output from the module
I/O
Bi-directional Input / Output
OD
Open drain output from the module
I 3.3V
Input 3.3V tolerant
I 5V
Input 5V tolerant
O 3.3V
Output 3.3V signal level
O 5V
Output 5V signal level
I/O 3.3V
Bi-directional signal 3.3V tolerant
I/O 5V
Bi-directional signal 5V tolerant
I/O 3.3V
SB
Input or output 3.3V tolerant active in standby state
DDC
Display Data Channel
PCIE
PCI Express compatible differential signal
PEG
PCI Express Graphics
SATA
Serial ATA specification Revision 2.6 and 3
LVDS Low
Voltage
Differential
Signal - 330 mV nominal; 450 mV maximum differential signal
P
Power Input / Output
REF
Reference voltage output. May be sourced from a Module power plane.
PDS
Pull-down strap. A Module output pin that is either tied to GND or is not connected.
Used to signal Module capabilities to the Carrier Board.
PU
PU (pull-up) resistor on module
PD
PD (pull-down) resistor on module
