2-4-3 Interrupt Control Registers

Interrupt control registers consist of the following: a non-maskable interrupt control

register (NMICR), external interrupt control registers (IRQnICR), and internal

interrupt control registers (TMnICR, TBICR, SCnICR, ATCICR, ADICR).

■Non-maskable Interrupt Control Register (NMICR)

Non-maskable interrupt factors are stored in the non-maskable interrupt control

register (NMICR), and are used when a non-maskable interrupt is generated.

Figure 2-4-2 Non-maskable Interrupt Control Register (NMICR: X'03FE1', R/W)

■External Interrupt Control Registers (IRQnICR)

The external interrupt control registers (IRQnICR) control the interrupt level, valid

edge, and request/enable.

Figure 2-4-3 External Interrupt Control Register

(IRQnICR: X'03FE2' to X'03FE3', X'03FEB' to X'03FED', R/W)

Chapter 2 Basic CPU Functions
34 Interrupts
01245673
(at reset: ------0-)
NMICR
0
1
No interrupt request
Watchdog interrupt request flag
Happens interrupt request
WDIR
WDIR
xxxLV1
Interrupt level flag for external interrupt
xxxLV0
01245673
(at reset: 000---00)
IRQnICR
0
1
No interrupt request
External interrupt request flag
Happens interrupt request
xxxIE
xxxIR
0
1
Disable interrupt
External interrupt enable flag
Enable interrupt
xxxIE
0
1 Rising edge
External interrupt valid edge flag
Falling edge
The CPU has interrupt levels from 0 to 3.
This flag sets the interrupt level for interrupt requests.
REDGn∗
xxxIRxxxLV1xxxLV0
REDGn
———
∗ n=0,1,2,3,4
By setting xxxLVn to '11' (level
3), the corresponding interrupt
vector will be disabled,
regardless of the state of the
interrupt enable and interrupt
request flags.
Be sure to use the MIE flag of
the PSW register to write to all
interrupt control registers.