Emerson / Motorola MVME133XTS VMEbus Module

The Emerson/Motorola MVME133XTS is a 32-bit VMEbus monoboard microcomputer engineered for embedded and industrial real-time control applications. Built around a 25 MHz Motorola MC68020 processor paired with a 25 MHz MC68882 Floating Point Coprocessor, this double-high VME module delivers deterministic processing for data-intensive tasks. The board integrates 4 MB of onboard DRAM, up to 256 KB of ROM/PROM/EPROM/EEPROM, and 8192 bytes of battery-backed SRAM on an M48T18 real-time clock module. Dual multi-protocol serial ports (Z8530) support EIA-232-D and EIA-485/EIA-422 communications, while a dedicated debug port provides front-panel EIA-232-D access. VMEbus master/slave functionality includes system controller capability, Level 3 arbiter, programmable interrupt handling across all seven levels, and dynamic configuration for 16/32-bit data width and 24/32-bit address space via jumpers.

Technical Specifications

Processor: Motorola MC68020 at 25 MHz

Floating Point Coprocessor: Motorola MC68882 at 25 MHz

Memory: 4 MB DRAM (32-bit), 256 KB ROM/PROM/EPROM/EEPROM (four 28-pin JEDEC sockets, two 16-bit banks), 8192 bytes battery-backed SRAM

VMEbus Interface: A32/D32 transfers, System Controller, Level 3 Arbiter, single-level bus requester, VMEbus interrupter (status ID $FF), interrupt handler for levels 0–7, dynamic width/address configuration

Timers: Tick timer, watchdog timer, three 8-bit programmable timers

Serial Ports: One EIA-232-D debug port (DB25), dual Z8530 ports (EIA-232-D and EIA-485/EIA-422)

Real-Time Clock: M48T18 with battery backup

Status/Control: Front-panel LEDs (FAIL, HALT, RUN, SCON), ABORT and RESET buttons, remote reset via P2 connector

Power: P1 and P2 connector supply, 25 W typical consumption

Operating Temperature: 0°C to 55°C

Cooling: Forced air required; 5 CFM at 320 LFM or 71 CFM axial fan typical

Form Factor: Double-high VME module, single slot

Key Features

32-bit data path with configurable 16/32-bit width

Selectable 24 or 32-bit addressing

Integrated watchdog timer for system reliability

Battery-backed real-time clock for time-critical operations

Multi-protocol serial I/O for diverse connectivity

Typical Applications Real-time industrial control, embedded data processing, VME-based instrumentation, and distributed control systems requiring floating-point computation.

Compatibility & Integration Fully compatible with VMEbus architecture. Supports standard and extended addressing modes. Configurable as system controller or peripheral module. Requires adequate forced-air cooling and dual power supply connections.