Chapter 3 Pin Assignments - Advantech SOM-5780 Design Manual

Chapter 3 Pin Assignments

This chapter describes pin assignments and IO characteristics for the 440 pin SOM-
Express. It includes four parts (A, B, C, D). There are five types of pin assignments
for COM-Express. We chose type-2 pin assignments on the SOM-Express. Please
refer to the COM-Express specifications to get more information.
Figure 3-1 SOM-Express Diagram
Table 3.1 Conventions and Terminology
Convention
'#'
'+' and '-'
Terminology
Pin Types:
I
O
IO
OD
Power Pin Types
VCC2.5
VCC3
VSB3
VCC3/5
GND
PWR
AC on
AC off
Others
I/F
MISC
NC
P
RSVD
*1
REF
PDS
Notes:
1. PWR*: The power to this pin is supplied from the carrier board connected to the
power supply.
Please refer to Chapter 5 for detailed descriptions.
2.
Advantech SOM-Express Design Guide
Description
Active-Low Signals
Differential Pairs
Description
Input
Output
Bi-Directional
Open Drain
+2.5 V ± 5% Volts
+3.3 V ± 5% Volts
+3.3 V ± 5% Standby Power
+3.3 V and +5 V tolerance
System Ground
Power Supply
AC coupled on module
AC coupled off module
Interface
Miscellaneous Interface
Not Connected. Reserved.
Power Plane
Reserved pin
GND min, 3.3 V max
Reference voltage output. May
be sourced from a module
power plane.
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.
Chapter 3 Pin Assignments
Example
WAKE0#
SATA0_TX+, SATA0_TX-
31