490NRP25400可編程模塊，SCHNEIDER使用范圍
GCSR允許VMEbus主機(jī)重置本地總線。此功能非常危險，應(yīng)與一起使用小心本地重置功能是部分系統(tǒng)重置，而不是完整的系統(tǒng)重置，如通電重置或系統(tǒng)重置*。當(dāng)本地總線重置信號被斷言時，一個本地總線循環(huán)可能中止。VMEchip2已連接本地總線和VMEbus，如果中斷VMEbus的周期是有界的，可能會導(dǎo)致不穩(wěn)定的操作。
490NRP25400可編程模塊本地處理器和VMEbus主機(jī)應(yīng)使用中斷或郵箱位置；在正常通信中不應(yīng)使用重置。重置僅當(dāng)本地處理器停止或本地總線被掛起，重置是最后的手段。當(dāng)MVME162處于重置狀態(tài)時，忽略對其的任何VMEbus訪問。如果啟用全局總線計時器，生成總線錯誤。介紹本章介紹了塊上的MVME162嵌入式控制器圖表級別。功能描述概述了MVME162，然后詳細(xì)描述了MVME162的幾個塊電路。圖4-1顯示了MVME162主模塊的框圖。圖4-2顯示了奇偶校驗(yàn)DRAM夾層模塊的框圖。其他MVME162塊的說明，包括嵌入式MVME162中給出了ASIC和外圍芯片控制器程序員參考指南。有關(guān)功能的其余部分，請參閱它MVME162的說明。MVME162功能描述MVME162是一種高功能VMEbus單板計算機(jī)圍繞MC68040/MC68LC040芯片設(shè)計。它有1MB、4MB或8MB的DRAM、512KB的SRAM、1MB閃存、四個MVIP工業(yè)包接口和兩個串行端口（一個EIA-232-D DCE；一個EIA-232-D或EIA530 DCE/DTE）。選項(xiàng)包括SCSI大容量存儲接口、LAN以太網(wǎng)收發(fā)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.
