Specifications

PCIe/104 and PCI/104-Express Specification Revision 3.0 February 17, 2015 Page 1

1. INTRODUCTION

1.1. Purpose

This document defines the addition of PCI Express, the next generation serial interconnect bus, to the stackable 104,

EPIC, and EBX form factors. PCI Express was chosen because of its performance, scalability, wide market acceptance,

and growing silicon availability worldwide. The PCI Express architecture uses familiar software and configuration

interfaces of the conventional PCI bus architecture, but provides a new high-performance physical interface while

retaining software compatibility with the existing conventional PCI infrastructure.

PCI Express is a high performance I/O architecture used in both desktop and mobile applications. This hierarchical, point-

to-point interconnect works well with on-board and slot oriented architectures. The purpose of this Specification is to

adapt PCI Express to the stacked architecture employed with 104, EPIC and EBX form factors.

1.2. Standard Identification

A PCI-104 board with the addition of PCI Express becomes PCI/104-Express. A board with only the PCI Express

connector is called PCIe/104. Each of these configurations can be applied to EPIC and EBX as shown in Appendix B and

C. This allows full interchangeability with add-in devices across all PC/104 form factors.

1.3. Description

As computer technology continues to develop, the PC/104 community must expand to the new, widely accepted and

sustained technologies of the day. The PCI/104-Express Specification provides this next generation PC/104 platform with

a connector architecture that provides high-speed interfaces, maintains the ability to develop low-cost modules, and is

sustainable for the foreseeable future.

Key to its development was obtaining a high speed, 3-bank, stackable PCI Express connector for both up and down

stacking, while retaining the stackable PCI connector for backward compatibility to PCI-104, PC/104-Plus, and PC/104

peripheral modules. Figure 1-2 shows a basic view of the PCI/104-Express and PCIe/104 layouts.

PCI/104-Express Module

3-Bank Connector

Connector B

PCI – 120 Pin Connector

PCI Bus: 32 bit/33MHz

Connector A

PCI Express – 156 pin Connector

3.550 inches

(90.17 mm)

3.775 inches

(95.89 mm)

Bank 1 Bank 2 Bank 3

PCIe/104 Module