sh6631a SinoWealth Micro-Electronics Corp. Ltd, sh6631a Datasheet - Page 8

• Manufacturer Part Number: sh6631a
• Description: Mask 4-bit Microcontroller
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

Port Interrupt
The PORTA, PORTB and PORTC are used as port interrupt sources. Since PORT I/O is a bit programmable I/O, therefore only
the input port can generate an external interrupt. Any transitions from PORTB and PORTC input pins from V
generate an interrupt request (Default). when opt_pint is HIGH, PORTA1 ~ 3 ﹑ PORTB0 ~ 3 and PORTC0 as the port interrupt
source. Thus, further falling edge transitions can not be able to make interrupt request until all of the pins return to V
following is the port interrupt function block-diagram.
PORTC.3
PORTC.2
PORTC.1
PORTC.0
PORTB.3
PORTB.2
PORTB.1
PORTB.0
PC3OUT
PC2OUT
PC1OUT
PC0OUT
PB3OUT
PB2OUT
PB1OUT
PB0OUT
PORTA.3
PORTA.2
PORTA.1
PORTC.0
PORTB.3
PORTB.2
PORTB.1
PORTB.0
PA3OUT
PA2OUT
PA1OUT
PC0OUT
PB3OUT
PB2OUT
PB1OUT
PB0OUT
Figure. 4 PORT Interrupt Block Diagram
8
Default: opt_pint = 0
Option set: opt_pint = 1
FALLING EDGE
DETECTION
FALLING EDGE
DETECTION
INTERRUPT
INTERRUPT
PORT
PORT
SH6631A
DD
to GND will
DD
. The