National Instruments PC-DIO-96/PnP, Руководство пользователя

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Appendix D Register-Level Programming
©
National Instruments Corporation D-13 PC-DIO-96/PnP User Manual
Mode 0 Programming Example
The following example shows how to configure PPI A for various
combinations of mode 0 input and output. This code is strictly an
example and is not intended to be used without modification in a
practical situation.
Main() {
#define BASE_ADDRESS 0x180 /* Board located at address 180 */
#define APORTAoffset 0x00 /* Offset for PPI A, port A */
#define APORTBoffset 0x01 /* Offset for PPI A, port B */
#define APORTCoffset 0x02 /* Offset for PPI A, port C */
#define ACNFGoffset 0x03 /* Offset for PPI A, CNFG */
unsigned int porta, portb, portc, cnfg;
char valread; /* Variable to store data read from a port */
/* Calculate register addresses */
porta = BASE_A APORTAoffset;
portb = BASE_A APORTBoffset;
portc = BASE_A APORTCoffset;
cnfg = BASE_A ACNFGoffset;
9 10010001 Input Output Output Input
10 10010010 Input Output Input Output
11 10010011 Input Output Input Input
12 10011000 Input Input Output Output
13 10011001 Input Input Output Input
14 10011010 Input Input Input Output
15 10011011 Input Input Input Input
1
Upper nibble of port C
2
Lower nibble of port C
Table D-3. Mode 0 I/O Configurations (Continued)
Control Word Group A Group B
Number Bit
76543210
Port A Port C
1
Port B Port C
2