特点:

• 48位TTL I/O
• 单向8位和16位
• 双向8位和16位
• 双缓冲I/O模式
• 状态/中断输入
• 两个24位可编程定时器

VMIC /通用电气发那科VMIVME-2511采用两个摩托罗拉MC68230并行接口/定时器(PI/Ts)和一个MC68153总线中断模块(BIM)来支持所有电路板功能。

VMIVME-2511能够处理四个中断请求。每个PI/T模块能够处理两个请求:一个端口中断请求和一个定时器中断请求。四个中断请求信号(两个来自1号PI/T，两个来自2号PI/T)连接到BIM，为两个PI/T模块提供完全中断支持。每个PI/T模块都有两个用户可编程的片上中断向量寄存器。

MC68230并行接口/定时器为VMEbus系统提供多功能、双缓冲、并行接口和面向操作系统的定时器。并行接口以8或16位宽的单向或双向模式工作。在单向模式下，相关的数据方向寄存器决定端口引脚是输入还是输出。在双向模式下，数据方向寄存器被忽略，方向由四个握手引脚的状态动态决定。这些可编程握手引脚提供了一个足够灵活的接口，可以连接各种低速、中速或高速外设或其它计算机系统。PI/T端口允许使用矢量或自动矢量中断。它可以产生周期性中断、方波或在设定的时间周期后产生单个中断。此外，它还可以用于测量运行时间，或用作器件看门狗。

VMIVME-2511-200

Features:
48 bit TTL I/O
Unidirectional 8-bit and 16 bit
Bidirectional 8-bit and 16 bit
Double buffered I/O mode
Status/Interrupt Input
Two 24 bit programmable timers

VMIC/General Electric Fanuc VMIVME-2511 uses two Motorola MC68230 parallel interfaces/timers (PI/Ts) and one MC68153 bus interrupt module (BIM) to support all circuit board functions.

VMIVME-2511 can handle four interrupt requests. Each PI/T module can handle two requests: a port interrupt request and a timer interrupt request. Four interrupt request signals (two from PI/T No.1 and two from PI/T No.2) are connected to the BIM to provide full interrupt support for both PI/T modules. Each PI/T module has two user programmable on-chip interrupt vector registers.

MC68230 parallel interface/timer provides multifunctional, dual buffering, parallel interface, and operating system oriented timers for VMEbus systems. Parallel interfaces operate in unidirectional or bidirectional mode with a width of 8 or 16 bits. In unidirectional mode, the relevant data direction register determines whether the port pins are input or output. In bidirectional mode, the data direction register is ignored and the direction is dynamically determined by the state of the four handshake pins. These programmable handshake pins provide a flexible enough interface to connect various low-speed, medium speed, or high-speed peripherals or other computer systems. The PI/T port allows the use of vector or automatic vector interrupts. It can generate periodic interrupts, square waves, or a single interrupt after a set time period. In addition, it can also be used to measure running time or as a device watchdog.