WOODWARD 5466-258控制调速器,配置手册
本地总线到VMEbus接口，VMEbus到本地总线接口和本地VMEbus DMA控制器在MVME177由VMEchip2提供。VMEchip2还可以提供VMEbus系统控制器功能。请参阅单板机程序员参考中的VMEchip2详细编程信息指南。串行端口接口CD2401串行控制器芯片（SCC）用于实现四个串行端口。串行端口支持标准波特率（110至38.4K波特）。
WOODWARD 5466-258控制调速器这四个串行端口功能不同因为P2输入/输出连接器上的引脚数量有限。串行端口1是最小功能异步端口。它还与同步时钟信号线连接。请参阅单板机程序员绘图参考指南串行端口接口连接。所有四个串行端口使用EIA-232-D驱动器和接收器，位于主板和所有信号线均布线至输入/输出连接器。配置头位于主板上和MVME712x过渡板。外部输入/输出转换应使用MVME712x等板转换输入/输出工业标准连接器的连接器引脚。注：MVME177板硬件连接DTR信号从CD2401到连接器上标记为RTS的引脚P2.同样，CD2401的RTS连接到上的DTR因此，在编程CD2401时，断言需要RTS时使用DTR，需要RTS时使用RTSDTR。PCCchip2提供的接口允许16位CD2401出现在相邻地址；但是，访问CD2401必须为8位或16位。不允许32位访问。参考连接到CD2401数据表和单板中的PCCCIP2计算机程序员详细编程参考指南信息CD2401支持对本地内存的DMA操作。因为CD2401不支持中断所需的重试操作在VMEbus锁定条件下，CD2401 DMA控制器应未编程为访问VMEbus。硬件没有将CD2401限制为板载DRAM。
The local bus to VMEbus interface, the VMEbus to local bus
interface, and the local-VMEbus DMA controller functions on the
MVME177 are provided by the VMEchip2. The VMEchip2 can also
provide the VMEbus system controller functions. Refer to the
VMEchip2 in the Single Board Computers Programmer's Reference
Guide for detailed programming information. Serial Port Interface
The CD2401 serial controller chip (SCC) is used to implement the
four serial ports. The serial ports support the standard baud rates
(110 to 38.4K baud). The four serial ports are different functionally
because of the limited number of pins on the P2 I/O connector.
Serial port 1 is a minimum function asynchronous port.It also interfaces to the synchronous clock signal lines. Refer to the
Single Board Computers Programmer's Reference Guide for drawings of
the serial port interface connections.
All four serial ports use EIA-232-D drivers and receivers located on
the main board, and all the signal lines are routed to the I/O
connector. The configuration headers are located on the main board
and the MVME712x transition board. An external I/O transition
board such as the MVME712x should be used to convert the I/O
connector pinout to industry-standard connectors.
Note The MVME177 board hardware ties the DTR signal
from the CD2401 to the pin labeled RTS at connector
P2. Likewise, RTS from the CD2401 is tied to DTR on
P2. Therefore, when programming the CD2401, assert
DTR when you want RTS, and RTS when you want
DTR.
The interface provided by the PCCchip2 allows the 16-bit CD2401
to appear at contiguous addresses; however, accesses to the
CD2401 must be 8 or 16 bits. 32-bit accesses are not permitted. Refer
to the CD2401 data sheet and to the PCCchip2 in the Single Board
Computers Programmer's Reference Guide for detailed programming
information.
The CD2401 supports DMA operations to local memory. Because
the CD2401 does not support a retry operation necessary to break
VMEbus lockup conditions, the CD2401 DMA controllers should
not be programmed to access the VMEbus. The hardware does not
restrict the CD2401 to onboard DRAM.
