GE VMIVME-7751 VME Single Board Computer

Product Overview

-The Reflective Memory concept provides a very fast and efficient way to share data between distributed computer systems.

VMIC's VMIVME-5576 Reflective Memory interface allows data to be shared between up to

256 independent systems (nodes) at rates of up to 6.2 Mbyte/s. 

Each Reflective Memory board can be configured with up to 256 nodes.

Each Reflective Memory board can be configured with 256 Kbytes to 1 Mbyte of on-board SRAM. 

local SRAM allows fast reads of stored data.

Write data is stored in the local SRAM and broadcast to other Reflective Memory nodes via a high-speed fiber optic data path.

Data transfers between nodes are software transparent, so there is no I/O overhead.

Transmit and receive FIFOs buffer data during peak data rates to optimize CPU and bus performance and maintain high data throughput.

Reflective memory also allows interrupts to one or more nodes by writing to byte registers.

These interrupt (tertiary, user-definable) signals can be used to synchronize system processes or to follow any previous data.

Interrupts always follow the data to ensure that the data is received before the interrupt is acknowledged.

The VMIVME-5576 does not need to be initialized unless interrupts are used.

If interrupts are used, vectors and interrupt levels must be written to on-board registers and interrupts must be set.

Each node on the system has a unique identification number between 0 and 255.

The node number is determined by placing jumpers on the board during hardware system integration.

The node number can be read by software by accessing the on-board registers. 

In some applications, the node number helps determine the function of the node.

Features

The following brief overview of principal features illustrates the flexibility and

performance that is available with the VMIVME-3113A Board:

• 64 differential or single-ended inputs

• Powers up in AUTOSCANNING MODE - no software initialization required

• Continually digitizes all input channels and stores the results in a dedicated

channel dual-port register (AUTOSCANNING MODE)

• Six operating modes

— AUTOSCANNING MODE *

— RANDOM POLL MODE

— RANDOM INTERRUPT MODE

— SCANNING POLL MODE

— SCANNING INTERRUPT MODE

— AUTOSCANNING MODE with BIT

* Only for gain = 1 and a minimum of 16 channels.

• VMEbus interrupts may be programmed to interrupt upon completion of a

single A/D conversion, or upon completion of a 16 through 64-channel scan

(see “Analog-to-Digital (ADC) Control and Timing” on page 26)

• User-programmable interval timer supports scanning of all channels at periodic intervals

• Jumper-programmable gains of 1, 10, 100, 200 and 500

• Selectable A/D ranges of 0 to +10V, ±5V and ±10V

• Low-level and high-level inputs: ±10mV to ±10V

• Optional low pass filter

• Overvoltage protected inputs

• 5 x 106

Ω input impedance differential and 2x106

Ω input impedance

single-ended

• 33 kHz conversion rate at GAIN<500 (23kHz for GAIN = 500)

• Selectable output code: binary, offset binary, two's complement with sign extension

• Front panel Fail LED is under program control and may be used for any purpose

• Board ID register