The PICMG consortium has announced that the COM-HPC Carrier Board Design Guide is released and freely available on the PICMG website. The 160-page document provides electronics engineers and PCB layout engineers comprehensive information for designing custom system carrier boards for COM-HPC modules. COM-HPC—short for computer-on-module (COM)—high performance computing (HPC) – is a new open Computer-on-Module form factor standard that targets extremely high I/O and computer performance levels from high end clients up to the entry server class and even beyond.
Standard COM-HPC modules plug into a carrier or baseboard that is typically customized to the application. OEM benefits are fast and cost effective layout with high design security for application specific embedded and edge computing boards on the basis of open standards.
Especially helpful is the detailed discussion of the challenging module to carrier board Ethernet KR and KR4 backplane signaling, says PICMG. To save pins on COM-HPC modules, the sideband signals for the 10G / 25G / 40G / 100G Ethernet KR interfaces are serialized and must then be deserialized on the carrier board. The design guide provides instructions for this in a series of diagrams.
Additionally, the guide provides enhanced schematics and block diagrams for all provided interfaces such as Serial ATA, PCI Express up to Gen 5, USB4, Boot SPI, eSPI, eDP, MIPI-CSI, SoundWire, asynchronous serial port interfaces, I2C/I3C, GPIO, System Management Bus (SMBus), thermal protection and module type detection. PCB design rule summaries further enable engineers to efficiently design fully signal compliant COM-HPC carrier boards. Also, a section has been added to discuss mechanical considerations including heat spreader/module attachment, alternative board stack assemblies and board stiffeners for carrier boards. Information about all COM-HPC interfaces and a list of useful books to facilitate carrier board designs complete PICMG’s COM-HPC Carrier Board Design Guide.
Electronic design engineers and printed circuit board developers shall note that while the design guide contains additional detailed information it does not replace the PICMG COM-HPC specification. For complete guidelines on the design of COM-HPC compliant carrier boards and systems, it is necessary to refer to the full specification – the design guide is not intended to be the only source for any design decisions. Besides consulting the latest COM-HPC specification, it is also strongly recommended to use the module vendors’ product manuals as a reference. The design guide and base specification are accompanied by a Platform Management Interface Specification, and the COM‑HPC EEEP. The existing Embedded API (eAPI) specification also applies to COM-HPC.
The COM-HPC specification and the COM-HPC Carrier Board Design Guide are available for download on the PICMG website at picmg.org/openstandards/com-hpc/. A preview document is also available, as well as additional resources to learn more about the specification.
PICMG | www.picmg.org