HITACHI 69
5.3.2
Interrupt Control Register (ICR)
ICR is a 16-bit register that sets the input detection mode of the external interrupt input pins NMI
and
IRQ0
–
IRQ7
and indicates the input signal level to the NMI pin. A reset initializes ICR but the
standby mode does not.
Bit:
15
14
13
12
11
10
9
8
Bit name:
NMIL
—
—
—
—
—
—
NMIE
Initial value:
*
R
0
—
0
—
0
—
0
—
0
—
0
—
0
R/W:
R/W
Bit:
7
6
5
4
3
2
1
0
Bit name:
IRQ0S
IRQ1S
IRQ2S
IRQ3S
IRQ4S
IRQ5S
IRQ6S
IRQ7S
Initial value:
0
0
0
0
0
0
0
0
R/W:
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Note:
When NMI input is high: 1; when NMI input is low: 0
Bit 15 (NMI input level (NMIL)): NMIL sets the level of the signal input at the NMI pin.
NMIL cannot be modified. The NMI input level can be read to determine the NMI pin level.
Bit 15: NMIL
Description
0
NMI input level is low
1
NMI input level is high
Bits 14–9 (reserved): These bits always read as 0. The write value should always be 0.
Bit 8 (NMI edge select (NMIE)): NMIE selects whether the falling or rising edge of the
interrupt request signal to the NMI pin is sensed.
Bit 8: NMIE
Description
0
Interrupt is requested on falling edge of NMI input (initial value)
1
Interrupt is requested on rising edge of NMI input
Bits 7–0 (IRQ0–IRQ7 sense select (IRQ0S–IRQ7S)): IRQ0–IRQ7 select whether the falling edge or
low level of the
IRQ
inputs is sensed at the pins
IRQ0
–
IRQ7
.
Bits 7–0: IRQ0S–IRQ7S
Description
Interrupt is requested when
IRQ
input is low (initial value)
Interrupt is requested on falling edge of
IRQ
input
0
1