NEC POWERMATE OFFICE 2513 - SERVICE, Руководство по обслуживанию

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Technical Information 1-21
Serial Interface
The system has a buffered high-speed 16C550 UART compatible serial port (COM2)
integrated on the I/O controller. The serial port supports the standard RS-232C interface
(see Table 1-9). The buffered high-speed serial port supports transfer rates up to 19.2 KB.
This port allows the installation of high-speed serial devices for faster data transfer rates.
I/O addresses and interrupt levels for the channel are given Table 1-9. The interrupt level is
selectable via Setup to either IRQ3 or IRQ4. Software selectable base addresses are 3F8h,
2F8h, 3E8h, and 2E8h.
NOTE:
The COM1 serial port is factory set to
“disabled” to support the fax/modem.
Any interrupts used for the built-in serial port are
not available for ISA parallel ports.
Table 1-9 Serial Port Addressing and Interrupts
Starting I/O Address Interrupt Level Port
3F8h IRQ04 COM1*
2F8h IRQ03 COM2
3E8h IRQ04 COM3
2E8h IRQ03 COM4
* Disabled for fax/modem installation
Serial interface specifications include:
„
Baud rate up to 19.2 KB per second
„
Word length — 5, 6, 7, or 8 bits
„
Stop bit — 1, 1.5, or 2 bits
„
Start bit — 1 bit
„
Parity bit — 1 bit (odd parity or even parity).
Serial interface signals are output through the system board’s 9-pin, D-subconnector. The
connectors are located at the rear of the system unit. Pin locations for the serial interface
connector are shown in Appendix A.