National Instruments DAQCard-DIO-24, Руководство пользователя

Страница: 46 / 110

Appendix B Register-Level Programming
©
National Instruments Corporation B-5 DAQCard-DIO-24 User Manual
Register 2 are both set, the card passes
INTRB signals from the 82C55A on to
the host computer. If this bit is cleared,
the card does not pass the INTRB signals
on to the host computer, regardless of the
INTEN setting. Note that the 82C55A
does not generate INTRB signals unless
the INTEB bit on the 82C55A is set.
0 IRQ0 Interrupt Selection 0—If this bit and the
INTEN bit in Interrupt Control
Register 2 are both set, the card passes
INTRA signals from the 82C55A on to
the host computer. If this bit is cleared,
the card does not pass INTRA signals on
to the host computer, regardless of the
INTEN setting. Note that the 82C55A
does not generate INTRA signals unless
the INTEA bit (mode 1) or INTE1 or
INTE2 bit (mode 2) on the 82C55A is
set.
Interrupt Control Register 2
Bit Name Description
7–3, 1, 0 0 Reserved—These bits must be set to zero
for compatibility with future versions of
this card. However, older software that
sets these bits to 1 will still work with the
DAQCard-DIO-24.
2 INTEN Interrupt Enable—If this bit is set, the
DAQCard-DIO-24 can interrupt the host
computer. If this bit is cleared, the
DAQCard-DIO-24 interrupt line is put
into high-impedance mode, so other
devices can use the interrupt line.
D7 D6 D5 D4 D3 D2 D1 D0
0 0 0 0 0 INTEN 0 0