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 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.