Emerson MVME147 manual General Information, Introduction, Features, Modes of Operation

GENERAL INFORMATION

1

Introduction

The MVME147 MPU VMEmodule contains a port to the Small Computer Systems Interface (SCSI) bus. The hardware interface is the WD33C93 SCSI interface controller.

To relieve you of having to follow SCSI bus protocol, the SCSI firmware allows you to pass commands to the bus through high level command packets. Standard command packets are furnished, as well as custom SCSI sequence packets that you may easily modify to fit particular applications. With this method, the firmware interface can greatly speed up your software development cycle.

The SCSI firmware resides in two 128K x 8 EPROMs and is co-resident with MVME147Bug, the debug monitor for the MVME147 MPU VMEmodule.

Features

The SCSI firmware offers the following features:

❏Custom SCSI sequence packets that allow creation of customized functions

❏TARGET role

❏Multitasking -- up to 64 concurrent peripheral devices

❏High level support of SCSI devices

❏Interrupt mode allows real-time applications

❏Polled mode -- non-interrupt operation

❏DMA with memory/scatter/gather

❏Multiple-user interface allows concurrent operation through independent drivers

❏Six entry points

❏Thirty-one "canned" or standard function packets

Modes of Operation

When using the SCSI firmware, you have a choice of two modes of operation: Interrupt mode and polled mode.