Curtiss-Wright / VMETRO / Micro Memory MM-6490DR High Speed, Dual-Port 2GB VME / VME64 / RACEway Buffer Memory

The MM-6490DR is a high-speed, dual-port buffer memory board for VME/VME64/RACEway systems requiring real-time data acquisition and processing. Available in 128 MB to 2 GB configurations, it delivers burst-mode transfer rates exceeding 160 MB/s on RACEway and sustained 80 MB/s block transfers on VMEbus. Dual independent memory ports switch-selectable on 1 MB boundaries enable flexible system integration. Byte-wise parity generation and checking with BERR status reporting protect data integrity across transfers. The board supports 8/16/32/64-bit data paths and sequential block transfer modes (256/2 KB, MBLT 2 KB, RACEway 2 KB). All units undergo 48-hour burn-in and memory diagnostics with temperature cycling from 0–60°C to verify operational reliability.

## Technical Specifications

• **Memory Capacity:** 128 MB, 256 MB, 512 MB, 1 GB, 2 GB
• **VMEbus Interface:** VME Rev. D compliant; 32-bit addressing; 8/16/32/64-bit data width (UAT); block transfer (BLT) read/write at 100/30 MB/s
• **RACEway Interface:** RACEway REV 1.4 compliant; 32-bit multiplexed data transfer; burst-mode operation exceeding 160 MB/s
• **Block Transfer Performance:** VMEbus at 80 MB/s; sequential modes support 256/2 KB, MBLT 2 KB, RACEway 2 KB
• **Control & Status:** Jumper-selectable in VME short I/O space (A16); byte-wide parity error reporting via BERR
• **Operating Modes:** Read, Write, Read-Modify-Write, Refresh
• **Parity:** Per-byte generation and checking; “Write-Wrong” diagnostic mode enabled
• **Form Factor:** Single-slot VME
• **Qualification:** 48-hour burn-in and memory diagnostics; temperature cycling 0–60°C

## Key Features

• Dual independent memory ports with granular 1 MB switch selection
• Dual-interface design supporting both legacy VME and high-speed RACEway architectures
• Byte-level parity with diagnostic write-wrong capability
• Address modifiers for long word, word, and byte transfers (A32/A24)

## Typical Applications

• Real-time signal processing in VME-based test and measurement systems
• High-throughput data buffering in embedded computing platforms
• COTS integration in RACEway-based defense and aerospace systems

## Compatibility & Integration

Fully compliant with VME Rev. D and RACEway REV 1.4 standards. Supports both 32-bit VMEbus and 32-bit RACEway multiplexed transfers for heterogeneous backplane environments.