Sample Program - NorthStar HSIO-4 User's & Technical Manual

3.2.4

SAMPLE PROGRAM

North Star HSIO-4
This section provides an example of how to
program the four HSIO-4 ports for use with
four asynchronous RS-232 terminals and/or
printers. Programming other configurations
requires a detailed familiarity with USART
operation. For the convenience of the
programmer, a complete manufacturer data sheet
for the USART is reproduced in Appendix B.
The following sample program:
1. checks input status and inputs a
character for each of the four ports;
2. checks output status and outputs a
character for each of the four ports;
3. initializes the HSIO-4 board.
Nine routines are given:
CINA inputs a character from port A
CINB inputs a character from port B
inputs a character from port C
CINC
CIND inputs a character from port D
COUTA outputs
COUTB outputs
COUTC outputs
COUTD outputs
INIT initializes the HSIO-4 board
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a character to port A
a character to port B
a character to port C
a character to port D
User/Technical Manual