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IEC 11518-2-02: High-Performance Parallel Interface – Mechanical, Electrical and Signaling Protocol Specification
Interoperability and Performance Benchmark for High-Speed Data Transmission Systems
IEC 11518-2-02 (adopted as CAN/CSA-ISO/IEC 11518-2-02) is the defining document for the physical layer of the High-Performance Parallel Interface (HIPPI). This standard specifies the mechanical, electrical, and signaling protocol characteristics for point-to-point parallel data links operating at rates up to 100 MB/s. Originally developed to interconnect supercomputers, mass storage systems, and high-performance networks, it remains relevant in legacy and specialized applications requiring deterministic low-latency data transfer.
1. Scope of IEC 11518-2-02
The standard is part of the ISO/IEC 11518 series and covers the Physical Layer (PH) of HIPPI. Its scope includes:
- Mechanical interface: connector type, pin assignments, cable requirements.
- Electrical specifications: signal levels, termination, timing, and power distribution.
- Signaling protocol: link initialization, data framing, flow control, and error detection.
The standard applies to both 32-bit and 64-bit data path implementations. It is intended for use in equipment that requires high-speed parallel communication over distances up to 25 meters (electrical) and extended ranges with repeaters.
2. Technical Requirements
2.1 Mechanical Interface
The standard defines a 50-pin connector (for 32-bit data) or 100-pin connector (for 64-bit data) with specific shielding and keying. Cable assemblies must maintain impedance of approximately 110 Ω differential and ensure signal skew below 1 ns.
2.2 Electrical Characteristics
Differential ECL (Emitter-Coupled Logic) signaling is used, providing noise immunity and low voltage swing (0.8 V to 1.6 V differential). The standard mandates precise termination networks and derating for cable length.
2.3 Signaling Protocol
HIPPI uses a request/acknowledge handshake for connection-oriented data delivery. The data bus is clocked with a synchronous strobe, and the protocol defines frames, packets, and connection states.
Tip: When designing HIPPI interfaces, pay close attention to PCB layout to maintain matched differential trace lengths and avoid impedance discontinuities.
| Parameter | Specification |
|---|---|
| Signaling type | Differential ECL |
| Data rate (32-bit) | 100 MB/s |
| Data rate (64-bit) | 200 MB/s |
| Connector (32-bit) | 50-pin shielded (micro ribbon or equivalent) |
| Connector (64-bit) | 100-pin shielded |
| Maximum cable length (point-to-point) | 25 meters |
| Differential impedance | 110 Ω ± 10% |
| Signal swing | 0.8 V – 1.6 V |
| Skew budget | ≤ 1 ns |
Caution: Exceeding the specified cable length or neglecting termination can cause signal reflections and data errors. Always use high-quality shielded twisted-pair cables.
3. Implementation Highlights
Integrating a HIPPI interface based on IEC 11518-2-02 requires careful attention to the physical medium. The differential ECL signaling demands tight control of impedance throughout the link — from driver output through connector and cable to receiver input. Termination at both ends (Thevenin equivalent to –2 V) must be present.
For 64-bit implementations, the standard doubles the number of data signals, effectively doubling throughput while maintaining the same clock rate. Skew compensation can be achieved via training sequences specified in the protocol.
Best Practice: Use matched-length cable assemblies and differential pair routing. Perform eye-diagram testing at 100 MHz to validate signal integrity.
The signaling protocol includes retransmission on error and requires a pre‑defined connection setup sequence. Designers should implement state machines that comply with the HIPPI‑PH control signals: Request, Connect, Ready, and Valid.
Non-Compliance Risk: Failure to comply with timing requirements (e.g., handshake response times) may lead to link instability or disconnection. Always verify conformance to the standard’s crucial timing parameters.
4. Compliance and Testing Notes
Testing for compliance with IEC 11518-2-02 typically involves verifying mechanical dimensions, electrical parameters (voltage levels, timing jitter), and protocol behavior. Specialized HIPPI test equipment can generate traffic and capture violations.
Although the standard has been largely superseded by serial interfaces (Fibre Channel, InfiniBand), it remains in use in certain defense, aerospace, and industrial applications. The Canadian adoption (CAN/CSA‑ISO/IEC 11518‑2‑02) ensures alignment with international specifications.
When certifying a product, provide complete documentation of the physical layer design, test results, and integration notes. Many organizations require third-party conformance testing for interoperability.
Frequently Asked Questions
Q: What data rate does IEC 11518-2-02 support?
A: The standard specifies a 32‑bit data path at 100 MB/s (800 Mbit/s) and a 64‑bit data path at 200 MB/s (1.6 Gbit/s), using differential ECL signaling.
A: The standard specifies a 32‑bit data path at 100 MB/s (800 Mbit/s) and a 64‑bit data path at 200 MB/s (1.6 Gbit/s), using differential ECL signaling.
Q: What is the maximum cable length?
A: The maximum point-to-point electrical cable length is 25 meters. Longer distances can be achieved using repeaters or fiber optic extensions (defined in other parts of the HIPPI family).
A: The maximum point-to-point electrical cable length is 25 meters. Longer distances can be achieved using repeaters or fiber optic extensions (defined in other parts of the HIPPI family).
Q: Is IEC 11518-2-02 still relevant today?
A: While newer interfaces like Fibre Channel and InfiniBand offer higher performance, HIPPI is still used in legacy high‑performance computing environments and specialized systems where deterministic latency is critical.
A: While newer interfaces like Fibre Channel and InfiniBand offer higher performance, HIPPI is still used in legacy high‑performance computing environments and specialized systems where deterministic latency is critical.
Q: What is the difference between IEC 11518-2-02 and other parts of the 11518 series?
A: Part 2 (PH) defines the physical layer. Other parts cover framing protocol (FP), switch control (SC), physical switch control (PSC), and mapping to other technologies.
A: Part 2 (PH) defines the physical layer. Other parts cover framing protocol (FP), switch control (SC), physical switch control (PSC), and mapping to other technologies.
Document Reference: IEC 11518-2-02 (CAN/CSA‑ISO/IEC 11518‑2‑02). This article is for informational purposes. Always refer to the latest published version for compliance requirements.
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