National Instruments PC-DIO-96 用户手册
Register-Level Programming
Chapter 4
PC-DIO-96 User Manual
4-8
© National Instruments Corporation
Interrupt Control Register 2
D7
D6
D5
D4
D3
D2
D1
D0
X
X
X
X
X
INTEN
CTRIRQ
CTR1
Bit
Name
Description
7–3
X
Don’t Care Bit.
2
INTEN
Global Interrupt Enable Bit—If this bit is set, the PC-DIO-96 can
interrupt the host computer. If this bit is cleared, the PC-DIO-96
interrupt line is put into high-impedance mode, so other devices
can use the interrupt channel selected by jumper W1.
interrupt the host computer. If this bit is cleared, the PC-DIO-96
interrupt line is put into high-impedance mode, so other devices
can use the interrupt channel selected by jumper W1.
1
CTRIRQ
Counter Interrupt Enable Bit—If this bit is set, the 8253 counter
outputs can interrupt the host computer. If this bit is cleared, the
counter outputs have no effect.
outputs can interrupt the host computer. If this bit is cleared, the
counter outputs have no effect.
0
CTR1
Counter 1 Enable Bit—If this bit is set, the output from counter 1
of the 8253 is connected to the interrupt request circuitry. In this
mode, counter 0 of the 8253 acts as a frequency scaler for
counter 1, which generates the interrupt. If CTR1 is cleared, the
output from counter 0 of the 8253 is connected to the interrupt
request circuitry. In this mode, counter 0 generates the interrupt.
For more information, see the section later in this chapter on
programming interrupts using the 8253.
of the 8253 is connected to the interrupt request circuitry. In this
mode, counter 0 of the 8253 acts as a frequency scaler for
counter 1, which generates the interrupt. If CTR1 is cleared, the
output from counter 0 of the 8253 is connected to the interrupt
request circuitry. In this mode, counter 0 generates the interrupt.
For more information, see the section later in this chapter on
programming interrupts using the 8253.