The release of the COM-HPC hardware specification 1.2 on Oct 3, 2023, brought a significant change – the definition of a smaller form factor module, the COM-HPC Mini. Beyond the compact size, it also introduces a new pinout, which consolidates the most critical features into a single connector.
The module connector itself also received major updates to make the mechanics even more rugged and enhance data throughput performance.
The PICMG working group initiated its “Mini” activities in July 2022. After 58 conference calls with an average of 13 attendees, the specification was released in October 2023. A revised carrier board design guide was released on February 24, 2024, to reflect the changes within the hardware specification. Let’s have a look at the most critical updates, starting with the size definition.
Mini Size
COM-HPC Mini is a specification for a small form factor Computer-on-Module (COM) within the broader COM-HPC ecosystem. The COM-HPC (Computer-on-Module High-Performance Computing) standard is an open, modular platform for building high-performance embedded computing systems. Designed to deliver high performance in a significantly reduced 95x70mm footprint, COM-HPC Mini extends the usability of COM-HPC Client to applications that previously could not accommodate the larger form factor. This includes applications with space and power constraints, such as high-end embedded logic in compact devices such as DIN-rail PCs for building/industrial automation control cabinets or portable test and measurement equipment.
The COM-HPC Mini specification differs from the larger COM-HPC Client and Server specifications in a few key areas. One of the most significant changes is the use of a single high-speed connector instead of two, which required slight changes to the interface. As a result, COM-HPC Mini modules are not compatible with the Client and Server specifications.
Despite having half the number of signal pins, COM-HPC Mini still provides 400 signal lanes, which is 90% of the capacity of COM Express Type 6 modules.
Another difference is that COM-HPC Mini modules require soldered memory. This design choice increases the ruggedness of the modules, providing higher resistance to shock and vibration, and improves efficiency.
While the COM-HPC 1.2 specification, which officially introduced the COM-HPC Mini form factor, wasn’t ratified until October 2023, the COM-HPC Mini pinout and dimensions were already finalized in December 2022, allowing PICMG members to begin designing compliant modules.
It’s important to note that COM-HPC Mini is not a replacement for other small form factor standards such as COM Express Mini. Instead, it should be viewed as a complementary standard that addresses evolving needs, particularly for applications that require high performance in a small form factor.
