MB91401
46
(Continued)
(2) NMI (Non Maskable Interrupt)
NMIs have the highest priority among the interrupt sources handled by this module.
An NMI is always selected whenever other types of interrupt sources occur at the same time.
• If an NMI occurs, the interrupt controller passes the information to the CPU :
Interrupt level : 15 (01111
B
)
Interrupt number : 15 (0001111
B
)
• NMI detection
NMIs are set and detected by the external interrupt/NMI controller. This module only generates an interrupt
level, interrupt number, and MHALTI upon NMI request.
• Suppressing DMA transfer upon NMI request
When an NMI request occurs, the MHALTI bit in the HRCL register is set to "1", suppressing DMA transfer. To
permit DMA transfer, clear the MHALTI bit to "0" at the end of the NMI routine.
Interrupt source
Interrupt number
Interrupt
level
Offset
Address of TBR
default
RN
Decimal
Hexa-
decimal
System reserved
68
44
2EC
H
000FFEEC
H
System reserved
69
45
2E8
H
000FFEE8
H
System reserved
70
46
2E4
H
000FFEE4
H
System reserved
71
47
2E0
H
000FFEE0
H
System reserved
72
48
2DC
H
000FFEDC
H
System reserved
73
49
2D8
H
000FFED8
H
System reserved
74
4A
2D4
H
000FFED4
H
System reserved
75
4B
2D0
H
000FFED0
H
System reserved
76
4C
2CC
H
000FFECC
H
System reserved
77
4D
2C8
H
000FFEC8
H
System reserved
78
4E
2C4
H
000FFEC4
H
System reserved
79
4F
2C0
H
000FFEC0
H
Used by INT instruction
80
to
255
50
to
FF
2BC
H
to
000
H
000FFEBC
H
to
000FFC00
H
Summary of Contents for MB91401
Page 71: ...MB91401 71 MEMO ...
