Справочник Пользователя для National Instruments PCI-DIO-96
Chapter 5
Register Map and Description
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National Instruments Corporation
5-5
PCI-DIO-96 User Manual
Table 5-2 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.
port C. Notice that bit 7 of the control word is cleared when
programming the set/reset option for the bits of port C.
Register Description for the 82C53
Figure 5-2 shows the control word format used to completely program
the 82C53. Bits 7 and 6 of the control word select the counter to be
programmed. Bits 5 and 4 select the mode by which the count data is
written to and read from the selected counter. Bits 3, 2, and 1 select the
mode for the selected counter. Bit 0 selects whether the counter counts
in binary or BCD format.
the 82C53. Bits 7 and 6 of the control word select the counter to be
programmed. Bits 5 and 4 select the mode by which the count data is
written to and read from the selected counter. Bits 3, 2, and 1 select the
mode for the selected counter. Bit 0 selects whether the counter counts
in binary or BCD format.
Table 5-2. Port C Set/Reset Control Words
Bit Number
Bit Set
Control Word
Bit Reset
Control Word
Bit Set or Reset
in Port C
0
0xxx0001
0xxx0000
xxxxxxxb
1
0xxx0011
0xxx0010
xxxxxxbx
2
0xxx0101
0xxx0100
xxxxxbxx
3
0xxx0111
0xxx0110
xxxxbxxx
4
0xxx1001
0xxx1000
xxxbxxxx
5
0xxx1011
0xxx1010
xxbxxxxx
6
0xxx1101
0xxx1100
xbxxxxxx
7
0xxx1111
0xxx1110
bxxxxxxx