490NRP25400可编程模块，SCHNEIDER使用范围

GCSR允许VMEbus主机重置本地总线。此功能非常危险，应与一起使用小心本地重置功能是部分系统重置，而不是完整的系统重置，如通电重置或系统重置*。当本地总线重置信号被断言时，一个本地总线循环可能中止。VMEchip2已连接本地总线和VMEbus，如果中断VMEbus的周期是有界的，可能会导致不稳定的操作。

490NRP25400可编程模块本地处理器和VMEbus主机应使用中断或邮箱位置；在正常通信中不应使用重置。重置仅当本地处理器停止或本地总线被挂起，重置是最后的手段。当MVME162处于重置状态时，忽略对其的任何VMEbus访问。如果启用全局总线计时器，生成总线错误。介绍本章介绍了块上的MVME162嵌入式控制器图表级别。功能描述概述了MVME162，然后详细描述了MVME162的几个块电路。图4-1显示了MVME162主模块的框图。图4-2显示了奇偶校验DRAM夹层模块的框图。其他MVME162块的说明，包括嵌入式MVME162中给出了ASIC和外围芯片控制器程序员参考指南。有关功能的其余部分，请参阅它MVME162的说明。MVME162功能描述MVME162是一种高功能VMEbus单板计算机围绕MC68040/MC68LC040芯片设计。它有1MB、4MB或8MB的DRAM、512KB的SRAM、1MB闪存、四个MVIP工业包接口和两个串行端口（一个EIA-232-D DCE；一个EIA-232-D或EIA530 DCE/DTE）。选项包括SCSI大容量存储接口、LAN以太网收发器接口和非VMEbus版本。

The GCSR allows a VMEbus master to reset the local bus.

This feature is very dangerous and should be used with

caution. The local reset feature is a partial system reset, not

a complete system reset such as powerup reset or

SYSRESET*. When the local bus reset signal is asserted, a

local bus cycle may be aborted. The VMEchip2 is connected

to both the local bus and the VMEbus and if the aborted

cycle is bound for the VMEbus, erratic operation may result.

Communications between the local processor and a

VMEbus master should use interrupts or mailbox locations;

reset should not be used in normal communications. Reset

should be used only when the local processor is halted or

the local bus is hung and reset is the last resort.

Any VMEbus access to the MVME162 while it is in the reset state is ignored. If

a global bus timer is enabled, a bus error is generated.Introduction

This chapter describes the MVME162 Embedded Controller on a block

diagram level. The Functional Description provides an overview of the

MVME162, followed by a detailed description of several blocks of MVME162

circuitry. Figure 4-1 shows a block diagram of the MVME162 main module.

Figure 4-2 shows a block diagram of the parity DRAM mezzanine module.

Descriptions of other MVME162 blocks, including programmable registers in

the ASICs and peripheral chips, are given in the MVME162 Embedded

Controller Programmer’s Reference Guide. Refer to it for the rest of the functional

description of the MVME162.

MVME162 Functional Description

The MVME162 is a high-functionality VMEbus single board computer

designed around the MC68040/MC68LC040 chip. It has 1MB, 4MB, or 8MB of

DRAM, 512KB of SRAM, 1MB Flash memory, four MVIP IndustryPack

interfaces, and two serial ports (one EIA-232-D DCE; one EIA-232-D or EIA530 DCE/DTE). Options include an SCSI mass storage interface, a LAN

Ethernet transceiver interface, and a non-VMEbus version.