Fujitsu FR81S User Manual
CHAPTER 13: EXTERNAL INTERRUPT INPUT
7. Q&A
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : EXTERNAL INTERRUPT INPUT
FUJITSU SEMICONDUCTOR CONFIDENTIAL
13
7. Q&A
This section explains Q&A of the external interrupt input.
About Detection Levels and Their Setting Procedures
Four levels: ("L" level, "H" level, rising edge, falling edge)
Set the detection level bits as follows: (ELVRy:LBn, LAn) (n=0 to 7, y=0, 1).
Operation modes
Detection level bits (LBn, LAn) n=0 to 7
To perform "L" level detection
Set "00".
To perform "H" level detection
Set "01".
To perform rising edge detection
Set "10".
To perform falling edge detection
Set "11".
How to Make External Pins to Use for Input
See "CHAPTER: I/O PORTS".
About Interrupt Related Registers
See "CHAPTER: INTERRUPT CONTROL (INTERRUPT CONTROLLER)".
About Interrupt Types
Interrupt factors are only for external interrupts. There are no select bits.
How to Enable/Disable/Clear Interrupts
Interrupt request enable flag, interrupt request flag
Interrupt enable setting is done by the interrupt enable bit (ENIR0/ENIR1:EN0 to EN7).
Operation
Interrupt enable bit (ENn)
To disable interrupt requests
Set "0".
To enable interrupt requests
Set "1".
Interrupt request clear is done by the interrupt request bit (EIRR0/EIRR1:ER0 to ER7).
Operation
Interrupt request bit (ERn)
To clear interrupt requests
Write "0".
MB91520 Series
MN705-00010-1v0-E
486