1786-RPFPXLB模块，A-B英文使用说明
串行通信接口MVME172LX使用两个Zilog Z85230串行端口控制器来实现四个串行通信接口。每个接口支持CT、DCD、RTS和DTR控制信号，以及TXD和RXD发送/接收数据信号。因为串行时钟是在MVME172LX实现中省略了串行通信严格异步。MVME172LX硬件支持串行波特率速率为110b/s至38.4Kb/s。Z85230在中断确认期间提供中断矢量周期。该向量根据中断请求电平通过MC2chip编程。
1786-RPFPXLB模块参考本章中列出的Z85230数据表和MC2chipMVME172 VME嵌入式控制器的编程模型程序员参考指南，供参考。Z85230s作为DTE（数据终端设备）与EIA232-D信号电平连接。四个串行端口路由到四个RJ-45MVME172LX前面板上的连接器。IP接口MVME172LX上最多可以安装两个IP模块。IPs和MVME172LX之间的接口是IndustryPack接口控制器（IP2）ASIC。两个3M公司提供IPs接入连接器位于MVME172LX前面板后面。请参阅MVME172 VME嵌入式控制器中的IP2章节IP接口详细功能的程序员参考指南。以太网接口MVME172LX使用Intel 82596CA LAN协处理器实现以太网收发器接口。82596CA访问本地RAM使用DMA操作来执行其正常功能。因为82596CA具有较小的内部缓冲区，VMEbus具有未定义的延迟期，如果DMA编程为访问VMEbus。因此，82596CA不应编程访问VMEbus。每个具有以太网接口的MVME172LX都分配了一个以太网车站地址。地址是$08003E2xxxxx，其中xxxxx是唯一的分配给电路板的5位数字（即，每个MVME172LX都有一个xxxxx的值不同）。每个电路板都有一个以太网站地址，显示在标签上至VMEbus P2连接器。此外，包以太网地址存储在BBRAM的配置区域中。那个is，08003E2xxxxx存储在BBRAM中。前四个字节（08003E2x）读取为$FFFC1F2C；下两个字节（xxxx）在以下位置读取：$FFFC1F30。MVME172调试器能够检索或设置以太网地址。
Serial Communications Interface
The MVME172LX uses two Zilog Z85230 serial port controllers to
implement the four serial communications interfaces. Each interface
supports CTS, DCD, RTS, and DTR control signals, as well as the TXD
and RXD transmit/receive data signals. Because the serial clocks are
omitted in the MVME172LX implementation, serial communications are
strictly asynchronous. The MVME172LX hardware supports serial baud
rates of 110b/s to 38.4Kb/s.
The Z85230 supplies an interrupt vector during interrupt acknowledge
cycles. The vector is modified based upon the interrupt source within the
Z85230. Interrupt request levels are programmed via the MC2chip. Refer
to the Z85230 data sheet listed in this chapter, and to the MC2chip
Programming Model in the MVME172 VME Embedded Controller
Programmer’s Reference Guide, for information.
The Z85230s are interfaced as DTE (data terminal equipment) with EIA232-D signal levels. The four serial ports are routed to four RJ-45
connectors on the MVME172LX front panel.
IP Interfaces
Up to two IP modules may be installed on the MVME172LX as an option.
The interface between the IPs and MVME172LX is the IndustryPack
Interface Controller (IP2) ASIC. Access to the IPs is provided by two 3M
connectors located behind the MVME172LX front panel. Refer to the
chapter on the IP2 in the MVME172 VME Embedded Controller
Programmer’s Reference Guide for detailed features of the IP interface. Ethernet Interface
The MVME172LX uses the Intel 82596CA LAN coprocessor to
implement the Ethernet transceiver interface. The 82596CA accesses local
RAM using DMA operations to perform its normal functions. Because the
82596CA has small internal buffers and the VMEbus has an undefined
latency period, buffer overrun may occur if the DMA is programmed to
access the VMEbus. Therefore, the 82596CA should not be programmed
to access the VMEbus.
Every MVME172LX that has an Ethernet interface is assigned an Ethernet
Station Address. The address is $08003E2xxxxx where xxxxx is the unique
5-nibble number assigned to the board (i.e., every MVME172LX has a
different value for xxxxx).
Each board has an Ethernet Station Address displayed on a label attached
to the VMEbus P2 connector. In addition, the six bytes including the
Ethernet address are stored in the configuration area of the BBRAM. That
is, 08003E2xxxxx is stored in the BBRAM. The upper four bytes
(08003E2x) are read at $FFFC1F2C; the lower two bytes (xxxx) are read at
$FFFC1F30. The MVME172 debugger has the capability to retrieve or set
the Ethernet address.
