This document provides a broad overview of HOST, including a high-level description of the Tier 1 and Tier 2 standards. It presents HOST’s role within the existing open architecture ecosystem, the objectives of the program, and the benefits of utilizing HOST.
HOST Standard Tier 1
The Tier 1 Standard provides an overview of the HOST framework as a whole. It defines the core tenets of HOST and establishes universal requirements that apply to all HOST Tier 2 Standards. It defines terminology that applies to all HOST documentation, and requirements that constrain the lower tiers. It presents a governing logical architecture to ensure a Tier 2 technology implementation fulfills the primary goals of the HOST Standard. More simply, it enforces the central concepts of modularity, interoperability, and interchangeability as the tenets that HOST strives to implement.
HOST Tier 2 OpenVPX Core Technology Standard
This Tier 2 Standard applies the OpenVPX embedded computing technologies to the HOST Tier 1 Standard architecture. Whereas Tier 1 establishes universal requirements, Tier 2 constrains those requirements specifically to the OpenVPX technologies, while maintaining the tenets of clarity, interoperability, and upgradeability established in the Tier 1 standard. However, all Tier 2 Standards are platform agnostic, so this standard does not incorporate specific requirements of target systems. Tier 2 also establishes requirements and guidelines for HOST implementation and conformance for Tier 3, incorporating pin mapping for card and slot profiles.
HOST Standard Tier 3 Specification Guide
The Tier 3 Specification Guide establishes the format for capturing the performance, design, and interface requirements for any HOST-aligned module. The guide instructs the author to capture all applicable requirements from the HOST Tier 2 OpenVPX Core Technology Standard as well as performance requirements derived from the target system. The HOST Standard Tier 3 Specification Guide, if adhered to, results in a complete and properly formatted document which can be used as a ‘source of truth’ for HOST conformance.
HOST Tier 3 Specification Examples
The provided Tier 3 Specifications contain the technical specifications for several HOST-aligned modules. Each has all the information required for a manufacturer to establish HOST conformance for a single module type, containing requirements for all aspects of the platform, and a verification matrix to allow conformance to be checked. The requirements are inherited from the Tier 2 OpenVPX Core Technology Standard, narrowing down both to the applicable constraints for each module type to be HOST compliant.