HD643303x Hitachi, HD643303x Datasheet - Page 103

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

5.3 Interrupt Sources
The interrupt sources include external interrupts (NMI, IRQ
5.3.1 External Interrupts
There are six external interrupts: NMI, and IRQ
can be used to exit software standby mode.
NMI: NMI is the highest-priority interrupt and is always accepted, regardless of the states of the
I and UI bits in CCR. The NMIEG bit in SYSCR selects whether an interrupt is requested by the
rising or falling edge of the input at the NMI pin. NMI interrupt exception handling has vector
number 7.
IRQ
The IRQ
•
•
•
Figure 5-2 shows a block diagram of interrupts IRQ
IRQn
Note: n = 4 to 0
ISCR settings can select whether an interrupt is requested by the low level of the input at pins
IRQ
IER settings can enable or disable the IRQ
assigned by four bits in IPRA (IPRA7 to IPRA4).
The status of IRQ
cleared to 0 by software.
0
to IRQ
input
0
0
to IRQ
to IRQ
4
Interrupts: These interrupts are requested by input signals at pins IRQ
4
4
, or by the falling edge.
interrupts have the following features.
Figure 5-2 Block Diagram of Interrupts IRQ
0
to IRQ
sense circuit
Edge/level
4
IRQnSC
interrupt requests is indicated in ISR. The ISR flags can be
Clear signal
0
0
88
to IRQ
to IRQ
0
to IRQ
S
R
4
4
interrupts. Interrupt priority levels can be
. Of these, NMI, IRQ
IRQnF
0
4
.
to IRQ
Q
IRQnE
4
0
) and 21 internal interrupts.
to IRQ
4
0
, IRQ
IRQn interrupt
request
1
, and IRQ
0
to IRQ
4
2
.