140CPU43412A处理器模块，SCHNEIDER使用书

中断确认映射本地总线通过以下方式将中断确认周期与其他周期区分开来：将二进制值%11放在TT1-TT0上。它还指定了以下级别：使用TM2-TM0进行确认。中断处理程序选择正在确认该级别内的设备。VMEbus内存映射本节描述了VMEbus查看的本地资源映射大师级。

VMEbus访问本地总线VMEchip2包括用于VMEbusto本地总线接口的用户可编程映射解码器。地图解码器允许您编程启动以及MVME162响应的结束地址和修饰符。

140CPU43412A处理器模块VMEbus短输入/输出内存映射VMEchip2包括用于GCSR的用户可编程地图解码器。GCSR映射解码器允许您编程VMEbus短输入/输出空间中的GCSR。软件初始化大多数功能是通过其他设备上的开关或跳线完成的通过在MVME162上设置控制寄存器来实现模块。通电时或者重置，包含162Bug调试包的EPROM设置许多寄存器的默认值。具体编程细节可通过研究M68040确定微处理器用户手册。然后检查所有MVME162的详细信息MVME162嵌入式控制器程序员手册中给出的板载寄存器参考指南。多微处理器编程注意事项良好的编程实践表明，一次只有一个MPU具有控制权MVME162控制寄存器。特别值得注意的是：❏ 修改地址映射的寄存器❏ 需要两个周期才能访问的寄存器❏ VMEbus中断请求寄存器本地重置操作本地重置（LRST）是系统重置（SRST）的子集。本地重置可以生成五种方式：❏ 看门狗计时器过期❏ 按下前面板重置开关（如果系统控制器功能正常已禁用）❏ 通过在GCSR中的板控制寄存器中断言一位❏ 通过SYSRESET*❏ 通过通电重置。

Interrupt Acknowledge Map

The local bus distinguishes interrupt acknowledge cycles from other cycles by

placing the binary value %11 on TT1-TT0. It also specifies the level that is

being acknowledged using TM2-TM0. The interrupt handler selects which

device within that level is being acknowledged.

VMEbus Memory Map

This section describes the mapping of local resources as viewed by VMEbus

masters.

VMEbus Accesses to the Local Bus

The VMEchip2 includes a user-programmable map decoder for the VMEbusto-local-bus interface. The map decoder allows you to program the starting

and ending address and the modifiers the MVME162 responds to.

VMEbus Short I/O Memory Map

The VMEchip2 includes a user-programmable map decoder for the GCSR.

The GCSR map decoder allows you to program the starting address of the

GCSR in the VMEbus short I/O space.

Software Initialization

Most functions that have been done with switches or jumpers on other

modules are done by setting control registers on the MVME162. At powerup

or reset, the EPROMs that contain the 162Bug debugging package set up the

default values of many of these registers.

Specific programming details may be determined by study of the M68040

Microprocessor User’s Manual. Then check the details of all the MVME162

onboard registers as given in the MVME162 Embedded Controller Programmer’s

Reference Guide.

Multi-MPU Programming Considerations

Good programming practice dictates that only one MPU at a time have control

of the MVME162 control registers. Of particular note are:

❏ Registers that modify the address map

❏ Registers that require two cycles to access

❏ VMEbus interrupt request registersLocal Reset Operation

Local reset (LRST) is a subset of system reset (SRST). Local reset can be

generated five ways:

❏ Expiration of the watchdog timer

❏ Pressing the front panel RESET switch (if the system controller function is

disabled)

❏ By asserting a bit in the board control register in the GCSR

❏ By SYSRESET*

❏ By powerup reset.