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Chapter 4
Register-Level Programming
© National Instruments Corporation
4-13
PC-DIO-24 User Manual
Bit
Name
Description (continued)
4
INTE2
Interrupt Enable Bit for Input—If this bit is set, interrupts are
enabled from the 82C55A for IBFA. Controlled by bit set/reset of
PC4.
3
INTRA
Interrupt Request Status—If INTE1 is high and IBFA is high, this
bit is high, indicating that an interrupt request is asserted for input
transfers. If INTE2 is high and OBFA* is high, this bit is high,
indicating that an interrupt request is asserted for output transfers.
2–0
I/O
Input/Output—Extra I/O status lines available if port B is not
configured for mode 1.
At the digital I/O connector, port C has the following pin assignments when in mode 2.
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
OBFA*
ACKA*
IBFA
STBA*
INTRA
I/O
or
Hand-
shaking
Group A
Group B
Mode 2 Programming Example
Main() {
#define BASE_ADDRESS
0x210
/* Board located at address 210. */
#define PORTAoffset
0x00
/* Offset for port A */
#define PORTBoffset
0x01
/* Offset for port B */
#define PORTCoffset
0x02
/* Offset for port C */
#define CNFGoffset
0x03
/* Offset for CNFG */
register unsigned int porta, portb, portc, cnfg;
char valread;
/* Variable to store data read from a
port */
/* Calculate register addresses. */
porta = BASE_A PORTAoffset;
portb = BASE_A PORTBoffset;
portc = BASE_A PORTCoffset;
cnfg = BASE_A CNFGoffset;
Summary of Contents for PC-DIO-24
Page 51: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 2 National Instruments Corporation...
Page 52: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 3 PC DIO 24 User Manual...
Page 53: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 4 National Instruments Corporation...
Page 54: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 5 PC DIO 24 User Manual...
Page 55: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 6 National Instruments Corporation...
Page 56: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 7 PC DIO 24 User Manual...
Page 57: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 8 National Instruments Corporation...
Page 58: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 9 PC DIO 24 User Manual...
Page 59: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 10 National Instruments Corporation...
Page 60: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 11 PC DIO 24 User Manual...
Page 61: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 12 National Instruments Corporation...
Page 62: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 13 PC DIO 24 User Manual...
Page 63: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 14 National Instruments Corporation...
Page 64: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 15 PC DIO 24 User Manual...
Page 65: ...Appendix C OKI 82C55A Data Sheet PC DIO 24 User Manual C 16 National Instruments Corporation...
Page 66: ...Appendix C OKI 82C55A Data Sheet National Instruments Corporation C 17 PC DIO 24 User Manual...