Xycom XVME-400, Manual

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XVME-400/40l/490/491 Manual
October, 1989
Chapter 1
INTRODUCTION
1.1 OVERVIEW
The XVME-400, XVME-401, XVME-490, and XVME-491 are Quad Serial I/O VMEbus-
compatible modules which provide a VME system with four serial communications
channels. The XVME-400 and XVME-401 are single-high, while the XVME-490 and
XVME-491 are double-high. The XVME-400 and XVME-401 access the I/O through the
JKl and JK2 connectors on the module front panel, whereas the XVME-490 and
XVME-491 route their I/O to the VMEbus P2 connector.
The XVME-400 and XVME-490 each provide four RS-232C serial ports, while the
XVME-401 and XVME-491 each provide four RS-485/422A serial ports. (Differences
among these modules are further detailed in Chapter 2, notably in Tables 2-1 and 2-2.)
Each module contains two 8530 Serial Communication Controller (SCC) chips, designated
SCC #l and SCC #2. The two SCC serial chips provide a variety of communication modes,
including asynchronous, byte-synchronous, and bit-oriented protocols. Each channel is
independently programmable and has its own baud rate generator.
The VMEbus interface directly maps the SCC chips into the short I/O address space,
starting on a jumper-selected 1 Kbyte boundary. The modules can also be jumpered to
generate an interrupt on any of the seven VMEbus interrupt levels. The two SCC chips
can generate a total of 16 different interrupt vectors.
Some features of the XVME-400/40l/490/491 modules include:
Four independent full-duplex serial I/O channels
RS-232C or RS485/422A operation
Serial
channels independently configurable for asynchronous,
monosynchronous, bisynchronous, or HDLC/SDLC message formats
Independent baud rate generators for each serial channel
Modem control
Receivers are quadruply buffered, transmitters double buffered
Complete VMEbus interrupter, jumper-selectable to any interrupt level
Programmable IACK vector, with vector alteration based on source of
interrupt
Line drivers for each channel are tri-stateable (controlled by software) to
allow multidrop operation (XVME-401 and XVME-491 only)
1-l