The Curtiss-Wright / VMETRO MIDAS-20 is a PMC carrier module that integrates two PCI Mezzanine Cards into VMEbus systems. It delivers full Master/Slave VME64 capability with integrated DMA, decoupling FIFOs, and a 33 MHz PCI local bus interface. The module supports VME data rates to 70 MBytes/sec and PCI throughput to 132 MBytes/sec, making it suitable for data acquisition, signal processing, and communications applications requiring modular I/O expansion.
## Technical Specifications
**VMEbus Interface**
• VME64 mode operation with data rates up to 70 MBytes/sec
• Master and slave capability: A32/A24/A16 addressing with D64 (MBLT)/D32/D16/D08 data widths
• Supports BLT, ADOH, RMW, and LOCK transfer modes
• Slot-1 System Controller capable
• Auto-Slot ID mechanism per VME64 specification
**PCI Interface**
• 33 MHz PCI local bus, fully compliant
• Theoretical peak data rate: 132 MBytes/sec
• Integral write-posting FIFOs for bandwidth optimization
• Programmable DMA controller with linked-list support
**Power Consumption**
• 5V supply (board idle): 0.5A typical
• 5V supply (board active): 1.0A typical
• 3.3V PMC support: available at ECO level C.3 or higher, 4A maximum
• 5V supply from VME backplane
**PMC Configuration**
• Dual PMC slot architecture
• Support for standard 5V and 3.3V PCI Mezzanine Cards
• EMC shielding via PMC filler panels for unused positions
**Optional RACEway Interface**
• MIDAS-20R variant includes PCI-to-RACEway crossbar interface (PXB)
• RACEway peak data rates: 160 MBytes/sec between nodes
• MIDAS RACEway bridge performance: 132 MBytes/sec peak, 100 MBytes/sec sustained
## Key Features
• Decoupled VME and PCI interfaces maximize throughput
• Interrupt transfer capability between PMC modules and VMEbus
• Front panel I/O provisions for direct external connections
• Standard VMEbus form factor
## Typical Applications
Data acquisition systems, real-time signal processing, communications interfaces, and modular I/O expansion in VME-based instrumentation platforms.
## Compatibility & Integration
Fully compatible with standard PCI Mezzanine Cards and VME64 backplanes. Supports industry-standard PMC modules for flexible system configuration.
