HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 164

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

5.2.5
An IRQ interrupt is requested when the external interrupt vector mode select bit (EXIMD) of the
interrupt control register (ICR) is set to 1. An IRQ interrupt corresponds to input at one of pins
IRL3–IRL0. Low-level sensing or rising/falling/both-edge sensing can be selected independently
for each pin by the IRQ sense select bits (IRQ00S–IRQ31S) in the IRQ control/status register
(IRQCSR), and a priority level of 0 to 15 can be selected independently for each pin by means of
interrupt priority register C (IPRC). Set the interrupt vector mode select bit (VECMD) of the
interrupt control register (ICR) to enable external input of vector numbers. External vector
numbers are 0 to 127, and are input to the external vector input pins (D7–D0) during the interrupt
vector fetch bus cycle. When an external vector is used, 0 is input to D7.
When an IRQ interrupt is accepted in external vector mode, the IRQ interrupt priority level is
output from the interrupt acceptance level output pins (A3–A0). The external vector fetch signal
(IVECF) is also asserted. The external vector number is read from signals D7–D0 at this time.
IRQ interrupt exception processing sets the interrupt mask bits (I3–I0) in the status register (SR) to
the priority level value of the IRQ interrupt that was accepted.
Table 5.3
IRL3
0
1
146
IRQ Interrupts
IRL Interrupt Priority Levels and Auto-Vector Numbers
IRL2
0
1
0
1
Pin
IRL1
0
1
0
1
0
1
0
1
IRL0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Priority
Level
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Vector
Number
71
70
69
68
67
66
65
64