COM Express
Encyclopedia
COM Express, a computer-on-module
(COM) form factor, is a highly integrated and compact PC
that can be used in a design application much like an integrated circuit component. Each COM Express Module COM integrates core CPU and memory functionality, the common I/O of a PC/AT, USB, audio, graphics (PEG
), and Ethernet
. All I/O signals are mapped to two high density, low profile connectors on the bottom side of the module.
Maximum available interfaces for the defined types:
An additional Ultra form factor also is under consideration for addition to future revisions of the COM Express specification. Ultra small modules following the type 1 and type 10 pin-outs and adhering to the connector positioning as defined within the specification are already of COMs vendors. This ultra small module measures a mere 55 x 84 mm.
. It's not freely available but can be purchased from the PICMG website.
The current revision 2.0 (PICMG COM.0 R2.0) was released in Fall 2010. The original revision 1.0 was released July 10, 2005.
Computer-on-module
A computer-on-module or System on Module is a type of single-board computer , a subtype of an embedded computer system. An extension of the concept of System on Chip , COM lies between a full-up computer and a microcontroller in nature.- Design :Today's COM modules are complete embedded computers...
(COM) form factor, is a highly integrated and compact PC
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
that can be used in a design application much like an integrated circuit component. Each COM Express Module COM integrates core CPU and memory functionality, the common I/O of a PC/AT, USB, audio, graphics (PEG
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
), and Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
. All I/O signals are mapped to two high density, low profile connectors on the bottom side of the module.
Types
There are 7 different pin outs defined in the specification. The most common used pin out is type 2. The latest pin-outs added in the revision 2.0 of the COM Express specification (available from www.picmg.org) are Type 6 and Type 10.Maximum available interfaces for the defined types:
- Type 1: Single connector (220 pin), 6 PCI Express lanes, no PEG, no PCI, no IDE, 4 SATA, 1 LAN
- Type 10: Single connector (220 pin), 4 PCI Express lanes, no PEG, no PCI, no IDE, 2 SATA, 1 LAN, single channel LVDS only, DDI, no VGA, 2 Serial COM
- Type 2: Double connector (440 pin), 22 PCI Express lanes, PEG, PCI, 1 IDE, 4 SATA, 1 LAN
- Type 3: Double connector (440 pin), 22 PCI Express lanes, PEG, PCI, no IDE, 4 SATA, 3 LAN
- Type 4: Double connector (440 pin), 32 PCI Express lanes, PEG, no PCI, 1 IDE, 4 SATA, 1 LAN
- Type 5: Double connector (440 pin), 32 PCI Express lanes, PEG, no PCI, no IDE, 4 SATA, 3 LAN
- Type 6: Double connector (440 pin), 24 PCI Express lanes, PEG, no PCI, no IDE, DDI (for DisplayPort, HDMI, DVI or SDVO), 4 SATA, 1 LAN, 2 Serial COM, USB 3.0
Size
The specification defines 3 module sizes:- Compact: 95 x 95 mm
- Basic: 95 x 125 mm
- Extended: 110 x 155 mm
An additional Ultra form factor also is under consideration for addition to future revisions of the COM Express specification. Ultra small modules following the type 1 and type 10 pin-outs and adhering to the connector positioning as defined within the specification are already of COMs vendors. This ultra small module measures a mere 55 x 84 mm.
Specification
The COM Express specification is hosted by PICMGPICMG
The PCI Industrial Computer Manufacturers Group is a consortium of over 227 companies. The group, founded in 1994, was originally formed to adapt PCI technology for use in high-performance telecommunications, military and industrial computing applications but its work has now grown to include...
. It's not freely available but can be purchased from the PICMG website.
The current revision 2.0 (PICMG COM.0 R2.0) was released in Fall 2010. The original revision 1.0 was released July 10, 2005.