WOODWARD 5466-258控制調(diào)速器,配置手冊
本地總線到VMEbus接口，VMEbus到本地總線接口和本地VMEbus DMA控制器在MVME177由VMEchip2提供。VMEchip2還可以提供VMEbus系統(tǒng)控制器功能。請參閱單板機(jī)程序員參考中的VMEchip2詳細(xì)編程信息指南。串行端口接口CD2401串行控制器芯片（SCC）用于實現(xiàn)四個串行端口。串行端口支持標(biāo)準(zhǔn)波特率（110至38.4K波特）。
WOODWARD 5466-258控制調(diào)速器這四個串行端口功能不同因為P2輸入/輸出連接器上的引腳數(shù)量有限。串行端口1是最小功能異步端口。它還與同步時鐘信號線連接。請參閱單板機(jī)程序員繪圖參考指南串行端口接口連接。所有四個串行端口使用EIA-232-D驅(qū)動器和接收器，位于主板和所有信號線均布線至輸入/輸出連接器。配置頭位于主板上和MVME712x過渡板。外部輸入/輸出轉(zhuǎn)換應(yīng)使用MVME712x等板轉(zhuǎn)換輸入/輸出工業(yè)標(biāo)準(zhǔn)連接器的連接器引腳。注：MVME177板硬件連接DTR信號從CD2401到連接器上標(biāo)記為RTS的引腳P2.同樣，CD2401的RTS連接到上的DTR因此，在編程CD2401時，斷言需要RTS時使用DTR，需要RTS時使用RTSDTR。PCCchip2提供的接口允許16位CD2401出現(xiàn)在相鄰地址；但是，訪問CD2401必須為8位或16位。不允許32位訪問。參考連接到CD2401數(shù)據(jù)表和單板中的PCCCIP2計算機(jī)程序員詳細(xì)編程參考指南信息CD2401支持對本地內(nèi)存的DMA操作。因為CD2401不支持中斷所需的重試操作在VMEbus鎖定條件下，CD2401 DMA控制器應(yīng)未編程為訪問VMEbus。硬件沒有將CD2401限制為板載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.
