SHB Express™ Overview

shbThe SHB Express™ specification upgrades the original PICMG 1.0 shbsxpressPCI-ISA specification, adding PCI Express slots for commercially available peripheral boards. Direct ISA interfaces are not supported on the SHB Express system host boards. Like PICMG 1.0, PICMG 1.3 is designed to move all of the active components that would normally be placed on a PC motherboard to a single plug-in board, or single board computer, called the System Host Board. With PICMG 1.3, the backplane; sometimes referred to as the system motherboard, may contain only connectors, which makes for much more reliable systems with low MTTR and extremely simple performance upgrades as new SHB’s with new chip sets become available.

SHB Express provides a common set of electrical and mechanical characteristics for the hardware designer.  The architecture generally follows the PCI Express and PCI(-X) Local Bus specifications.

The system host board (SHB), or PICMG 1.3 single board computer (SBC), is designed to interface with PCI Express peripherals on a compatible PICMG 1.3 backplane.  The PCI Express interconnects with the backplane can operate at x1, x4, x8, x16, and others depending on the capabilities of both the SHB and the backplane.

The optional PCI(-X) portion of the SHB interconnect with the backplane allows for 32- bit operation. The clock rate between the SHB and the backplane can be 33MHz, 66MHz, 100MHz, and 133MHz, depending on how the backplane and SHB are designed. There is also a pin used to enable PCI-X operation if both the SHB and the backplane are capable of operating in this mode.

The SHB Express specification maximizes system design flexibility in a wide variety of military, industrial, medical and telecommunication applications by drawing from the standard slot-card economies of scale with commercial off the shelf (COTS) PCI(-X) and PCI Express plug-in peripheral cards.

Key Benefits and Features

  • Enables today’s faster, multi-core processors & chipsets to handle data tasks faster by utilizing the high-speed serial interconnects available with PCI Express
  • Maximizes system design flexibility by supporting both the latest industry standard PCI Express, and legacy PCI and PCI-X plug-in slot cards
  • Simplifies power delivery design by providing extra power connections through the SHB’s edge connector
  • Provides advanced system diagnostics via the Intelligent Platform Management Interface or IPMI
  • Enables more system design flexibility by supporting optional routing of Serial ATA, USB and Ethernet connections from the SHB’s edge connectors to the SHB-Express compatible backplane

Family of Specifications

SHB Express
PICMG# Name Current Revision Date Description

SHB Express

Rev 1.0 2005-08-20

Defines PCI Express usage with options for PCI in a classic slot card form factor.

Target Applications

  • Military – Ordnance firing systems, UAV tracking & control ground-based stations and airborne surveillance systems
  • HPC/Big Data – GPGPU computing systems and big data storage
  • Industrial – Machine-to-Machine (M2M) communications, factory automation, wafer production and Human Machine Interface systems (HMI)
  • Medical – Diagnostic systems, robotic surgery control, electronic medical records
  • Telecommunications – Emergency dispatch centers (911), call centers, data centers 

System Requirements

  • PICMG 1.3 provides guidance on system host board (single board computer) and backplane design:
  • The allowable system host board/single board computer form factors include full-size and half-size SHB’s.  Full-size SHB’s shall have edge connectors A, B and C with a provision to support the optional edge connector D.
  • Several PICMG 1.3 backplane form factors are defined including 14-slot, 20-slot and 2U butterfly.  The PICMG 1.3 backplane’s SHB slot can be located in any slot location.  All expansion slots shall have 20.32mm (0.8”) board center-to-center spacing as defined in the PCI Express Card Electromechanical Specification.
  • Chassis design is not specified but commercial PC chassis are inexpensive and widely available