PCI-ISA Overview

The PICMG 1.0 PCI-ISA standard was the first PICMG standard that moved all of the pciishacomponents normally located on a PC motherboard to a single plug-in card or single board computer. Looking much like a standard ISA or PCI card, a PCI-ISA CPU card or SBC has two edge connectors on it – one for the PCI bus and one for the ISA bus. The “motherboard” is replaced with a simple “passive backplane” that has only connectors soldered to it. This backplane design standard was designed to be simple and robust, with a very low failure rate.

Standard PICMG 1.0 systems have several advantages over previous non-standard systems. First, they are more maintainable than a motherboard system and have a much lower mean time to repair (MTTR). Second, it is easy to upgrade to a newer and faster processor if desired. Third, passive backplane CPU’s are generally manufactured by industrial suppliers who provide configuration control and longer product lifetimes than those typical of the desktop world.

The more recent PICMG 1.3 standard has largely replaced PICMG 1.0 in the industrial computer marketplace.

Key Benefits and Features

  • Established the basic PICMG concept of having a plug-in SBC and passive backplane that supports industry standard interfaces and plug-in I/O cards in an industrial computer platform
  • Maximizes system design flexibility by supporting industry standard, plug-in slot cards that have standardized PCI or ISA parallel bus interface architectures

Family of Specifications

PCI-ISA
PICMG# Name Current Revision Date Description

PCI-ISA

Rev 2.0 1994-10-10

Defines the SBC form factor and the parallel bus interface connectors for PCI-ISA PICMG 1.0 Passive Backplanes.

Target Applications

  • Telecommunications, Industrial Automation, Mil/Aero, Data Acquisition, and Instrumentation

System Requirements

PICMG 1.0 provides guidance on the required PCI-ISA parallel interconnects needed on a single board computer plug-in slot card.  The standard also defines the corresponding SBC-to-backplane interface connections in order to support industrial computer system designs that maximize the number of standard PCI or ISA plug-in cards supported in a PICMG 1.0 system.