VMEchip2

2

Introduction

This chapter describes the VMEchip2 ASIC, local bus to VMEbus interface chip.

The VMEchip2 interfaces the local bus to the VMEbus. In addition to the VMEbus defined functions, the VMEchip2 includes a local bus to VMEbus DMA controller, VME board support features, and Global Control and Status Registers (GCSR) for interprocessor communications.

Summary of Major Features

Local Bus to VMEbus Interface:

Programmable local bus map decoder.

Programmable short, standard, and extended VMEbus addressing.

Programmable AM codes.

Programmable 16-bit and 32-bit VMEbus data width.

Software-enabled write posting mode.

Write post buffer (one cache line or one four-byte).

Automatically performs dynamic bus sizing for VMEbus cycles.

Software-configured VMEbus access timers.

Local bus to VMEbus Requester:

Software-enabled fair request mode;

Software-configured release modes:

Release-When-Done (RWD), and

Release-On-Request (ROR); and

Software-configured BR0*-BR3* request levels.

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Motorola MVME172 manual VMEchip2, Summary of Major Features