Справочник Пользователя для National Instruments PC-DIO-24

D2

D1

D0

D5

D4

D3

D7

D6

  
(high nibble)
1 = input
0 = output

Control Word
Flag

1 = mode set

 
00 = mode 0
01 = mode 1
1X = mode 2

Mode Selection

 
1 = input
0 = output

Port A

Port C

  
(low nibble)

1 = input
0 = output

Port C

 
0 = mode 0
1 = mode 1

Mode Selection

Group A

Group  B

Port B
1 = input
0 = output

Flag

D2

D1

D0

X

X

D3

D7

X

 
     
0 = bit set/reset

 
 1 = set
 0 = reset

           (000)
           (001)
           (010)
             :
             :
           (111)

Control Word

Bit Select

Bit Set/Reset

a.  Mode Set Word Format

b.  Bit Set/Reset Word Format

Figure 4-1.  Control-Word Formats

Table 4-2 shows the control words for setting or resetting each bit in port C.  Notice that bit 7 of
the control word is cleared when programming the set/reset option for the bits of port C.