M30622ECTFP MITSUBISHI [Mitsubishi Electric Semiconductor], M30622ECTFP Datasheet - Page 69

• Manufacturer Part Number: M30622ECTFP
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

Precautions for Interrupts
Figure 1.14.13. Switching condition of INT interrupt request
(5) Rewrite the interrupt control register
• To rewrite the interrupt control register, do so at a point that does not generate the interrupt request for
• When a instruction to rewrite the interrupt control register is executed but the interrupt is disabled, the
that register. If there is possibility of the interrupt request occur, rewrite the interrupt control register after
the interrupt is disabled. The program examples are described as follow:
interrupt request bit is not set sometimes even if the interrupt request for that register has been gener-
ated. This will depend on the instruction. If this creates problems, use the below instructions to change
the register.
Instructions : AND, OR, BCLR, BSET
Tentative Specifications REV.A
Example 1:
Example 2:
Example 3:
The reason why two NOP instructions (four when using the HOLD function) or dummy read are inserted
before FSET I in Examples 1 and 2 is to prevent the interrupt enable flag I from being set before the
interrupt control register is rewritten due to effects of the instruction queue.
S
pecifications in this manual are tentative and subject to change.
INT_SWITCH1:
INT_SWITCH2:
INT_SWITCH3:
FCLR
AND.B
NOP
NOP
FSET
FCLR
AND.B
MOV.W MEM, R0
FSET
PUSHC FLG
FCLR
AND.B
POPC
I
#00h, 0055h ; Clear TA0IC int. priority level and int. request bit.
I
I
#00h, 0055h ; Clear TA0IC int. priority level and int. request bit.
I
I
#00h, 0055h ; Clear TA0IC int. priority level and int. request bit.
FLG
; Disable interrupts.
; Four NOP instructions are required when using HOLD function.
; Enable interrupts.
; Disable interrupts.
; Dummy read.
; Enable interrupts.
; Push Flag register onto stack
; Disable interrupts.
; Enable interrupts.
(Enable the accepting of INTi interrupt request)
Set the interrupt priority level to level 1 to 7
Set the interrupt priority level to level 0
______
Clear the interrupt enable flag to “0”
Clear the interrupt request bit to “0”
Set the interrupt enable flag to “1”
Set the polarity select bit
(Disable
(Disable interrupt)
(Enable interrupt)
69
INTi
interrupt)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Mitsubishi microcomputers
M16C / 62T Group