HITACHI 63
5.1.3
Pin Configuration
INTC pins are summarized in table 5.1.
Table 5.1
INTC Pin Configuration
Name
Abbr.
I/O
Function
Nonmaskable interrupt input
pin
NMI
I
Inputs a non-maskable interrupt request
signal
Interrupt request input pins
IRQ0
–
IRQ7
IRQOUT
I
Inputs maskable interrupt request signals
Interrupt request output pin
O
Outputs a signal indicating an interrupt
source has occurred.
5.1.4
Registers
The interrupt controller has six registers as listed in table 5.2. These registers are used for setting
interrupt priority levels and controlling the detection of external interrupt input signals.
Table 5.2
Interrupt Controller Register Configuration
Name
Abbr.
R/W
Address*
2
Initial Value
Bus width
Interrupt priority register A
IPRA
R/W
H'5FFFF84
H'0000
8, 16, 32
Interrupt priority register B
IPRB
R/W
H'5FFFF86
H'0000
8, 16, 32
Interrupt priority register C
IPRC
R/W
H'5FFFF88
H'0000
8, 16, 32
Interrupt priority register D
IPRD
R/W
H'5FFFF8A
H'0000
8, 16, 32
Interrupt priority register E
IPRE
R/W
H'5FFFF8C
H'0000
8, 16, 32
Interrupt control register
Note:
1. H'8000 when pin NMI is high, H'0000 when pin NMI is low.
2. Only the values of bits A27–A24 and A8–A0 are valid; bits A23–A9 are ignored. For
details on the register addresses, see section 8.3.5, Description of Areas.
ICR
R/W
H'5FFFF8E
*1
8, 16, 32
5.2
Interrupt Sources
There are four types of interrupt sources: NMI, user break, IRQ, and on-chip peripheral module
interrupts.
Interrupt rankings are expressed as priority levels (0–16), with 0 the lowest and 16 the highest. An
interrupt set to level 0 is masked.