Curtiss-Wright / VMETRO / Micro Memory MM-6490R High Speed, Dual-Port 256MB VME / VME64 / RACEway Buffer Memory

The MM-6490R is a high-speed, dual-port 256MB buffer memory board engineered for VME/VME64/RACEway systems. This dual-port architecture enables concurrent memory access, delivering sustained throughput for data-intensive applications across VMEbus and RACEway interconnects. The board integrates the VIC068 VMEbus interface chip to maintain authentic VMEbus timing and cycle compliance.

## Technical Specifications

• Memory Capacity: 256MB (available in 128MB, 256MB, 512MB, 1GB, and 2GB configurations)
• VMEbus Data Widths: 8, 16, 32, and 64 bits (UAT — Unaligned Transfer supported)
• VMEbus Address Spaces: A32, A24, A16
• RACEway Data Width: 32-bit multiplexed
• VMEbus Block Transfer Rate: up to 80 Mbytes/sec
• RACEway Burst Mode Rate: exceeding 160 Mbytes/sec
• Error Detection: Bytewide parity generation and checking with Control Status Register (CSR) in short I/O address space; error status transmitted via BERR
• Interface Chip: VIC068 VMEbus interface
• Qualification: 48-hour memory diagnostics with burn-in; temperature cycling 0–60 °C

## Key Features

• Dual-port design for simultaneous access and enhanced system efficiency
• VME64 standards compliance for 8-, 16-, 32-, and 64-bit parallel architectures
• Supports both VMEbus and RACEway environments
• Parity error detection and status monitoring via CSR
• Authenticated VMEbus cycle timing via dedicated interface chip

## Typical Applications

High-performance VMEbus systems requiring sustained data buffering, real-time signal processing, and parallel computing architectures with demanding throughput specifications.

## Compatibility & Integration

Fully compatible with VME, VME64, and RACEway-based systems. The dual-port configuration integrates directly into existing VMEbus architectures without protocol conversion or external buffering.