Macrolink MVCS Sierra Asynchronous Serial Commux VME64 Module

The Macrolink MVCS Sierra is a VME64-based asynchronous serial communication controller delivering high-speed, multi-port serial I/O for industrial and embedded systems. This module supports 8 or 16 independent asynchronous serial lines with individual rates up to 1.5 Mbps and aggregate throughput to 48 Mbps. It interfaces to the VMEbus via A32/D32 slave transfers and reduces host CPU overhead through a 64-byte FIFO per UART and an interrupt pacing engine that consolidates interrupts at programmable intervals. The module accepts a 16550-style programming interface, ensuring driver portability across platforms. Serial interface options—RS-232, RS-422, RS-485, MIL-STD-188C, and buffered TTL—are selectable in 4-line groups via separately available line conditioning modules. Two 100-pin front panel connectors provide density and signal flexibility for modem control and general-purpose serial I/O. Extended FIFO configurations support aggregate rates exceeding 30 MB/s for reduced VMEbus bandwidth overhead. Address pipelining and combined FIFO status readback in single 32-bit accesses optimize real-time performance.

– Technical Specifications

• VMEbus Interface: A32/D32 slave transfers; IEEE 1014/IEC 821; ANSI/VITA 1-1994 compliance
• Serial Ports: 8 or 16 asynchronous lines
• Data Rates: Up to 1.5 Mbps per line; aggregate throughput to 48 Mbps
• FIFO Depth: 64-byte per UART; extended FIFOs available
• Baud Rate Support: Independent selection per port; up to 307.2 kbps (default device configurations)
• Programming Interface: 16550-style UART
• Front Panel Connectors: Two 100-pin high-density connectors

– Key Features

• Interrupt pacing engine reduces CPU overhead
• Mixed serial interface types in single module (RS-232, RS-422, RS-485, MIL-STD-188C, TTL)
• Combined FIFO status readable in one 32-bit VMEbus access
• Address pipelining support
• Optional P2 transition module available
• Line conditioning modules sold separately; support up to 12 signals per line

– Typical Applications

• Multi-port serial concentration in VME-based test and measurement systems
• Industrial real-time I/O controllers requiring low-latency asynchronous communication
• Embedded systems with high aggregate serial throughput demands

– Compatibility & Integration

Fully compliant with VME64 standards (IEEE 1014/IEC 821; ANSI/VITA 1-1994). 16550-style programming interface enables rapid driver development and cross-platform software reuse.