![](http://datasheet.mmic.net.cn/110000/M32186F8VFP_datasheet_3496152/M32186F8VFP_140.png)
INTERRUPT CONTROLLER (ICU)
5
5-16
32185/32186 Group Hardware Manual
Rev.1.10 REJ09B0235-0110 May 15, 07
Figure 5.5.2 Typical Handler Operation for Interrupts from Internal Peripheral I/O
5.5 Description of Interrupt Operation
Note 1: For operations at EIT acceptance and return from EIT, also see Section 4.3, "EIT Processing Procedure."
Note 2: Do not read the Interrupt Vector Register (IVECT) or write to the Interrupt Request Mask Register (IMASK)
in the EIT handler unless interrupts are disabled (PSW register IE bit = 0).
Note 3: To enable multiple interrupts, execute processing in [6] and [9].
Note 4: There are precautions to be taken when reenabling interrupts (by setting the IE bit to "1") after reading the
Interrupt Vector Register (IVECT). For details, see the Section 5.2.1, "Interrupt Vector Register (IVECT)."
The precautions apply to the Process [4], therefore, other processes are not required to add.
Also, there are precautions to be taken when reenabling interrupts (by setting the IE bit to "1") after writing
to the Interrupt Request Mask Register (IMASK). For details, see the Section 5.2.2, "Interrupt Request Mask
Register (IMASK)."
H'0000 0080
BRA instruction
Read Interrupt Vector
Register (IVECT)
Read ICU vector table
Branch to the interrupt handler
for each internal peripheral I/O
RTE
H'0080 0004
H'0000 0094
H'0000 013B
Interrupt
handler
EI (External Interrupt)
handler
EI (External Interrupt)
vector entry
Interrupt handler
start address
Program being
executed
Interrupt
generated
IVECT
Save BPC to the stack
Save PSW to the stack
Save general-purpose
registers to the stack
Restore BPC from the stack
Restore PSW from the stack
Restore general-purpose
registers from the stack
Read and save Interrupt
Request Mask Register
(IMASK) to the stack
IMASK
H'0080 0000
Set PSW register IE bit to 1
Clear PSW register
IE bit to 0
Restore Interrupt Request
Mask Register (IMASK)
from the stack
[1]
[2]
[3]
[5]
[7]
[8]
[9]
[6]
[10]
[11]
ICU vector table
(Note 1)
Hardware preprocessing
when EIT is accepted
Hardware postprocessing
when RTE instruction
is executed
Read and overwrite
Interrupt Request Mask
Register (IMASK)
[4]
[12]
(Note 2)
(Note 3)
(Note 4)
(Note 3)
(Note 2)
Interrupt
handler
[1] to [12]: Processing of EI
by interrupt handler