Справочник Пользователя для National Instruments PC-DIO-24
Register-Level Programming
Chapter 4
PC-DIO-24 User Manual
4-6
© National Instruments Corporation
Table 4-3. Mode 0 I/O Configurations
Control Word
Group A
Group B
Number
Bit
Port A
Port C
1
Port B
Port C
2
76543210
0
10000000
Output
Output
Output
Output
1
10000001
Output
Output
Output
Input
2
10000010
Output
Output
Input
Output
3
10000011
Output
Output
Input
Input
4
10001000
Output
Input
Output
Output
5
10001001
Output
Input
Output
Input
6
10001010
Output
Input
Input
Output
7
10001011
Output
Input
Input
Input
8
10010000
Input
Output
Output
Output
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
Mode 0 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;
char valread;
/* Variable to store data read from a
port */
/* Calculate register addresses. */
porta = BASE_ADDRESS + PORTAoffset;
portb = BASE_ADDRESS + PORTBoffset;
portc = BASE_ADDRESS + PORTCoffset;
cnfg = BASE_ADDRESS + CNFGoffset;
porta = BASE_ADDRESS + PORTAoffset;
portb = BASE_ADDRESS + PORTBoffset;
portc = BASE_ADDRESS + PORTCoffset;
cnfg = BASE_ADDRESS + CNFGoffset;