Renesas 4514 - Manual (Page 119)

APPLICATION
2.2 Interrupts
2-16 4513/4514 Group User’s Manual
2.2.3 Interrupt application examples
(1) External 0 interrupt
The INT0 pin is used for external 0 interrupt, of which valid waveforms can be chosen, which can
recognize the change of both edges (“H”
→
“L” or “L”
→
“H”).
Outline: An external 0 interrupt can be used by dealing with the change of edge (“H”
→
“L” or
“L”
→
“H”) in both directions as a trigger.
Specifications: An interrupt occurs by the change of an external signals edge (“H”
→
“L” or “L”
→
“H”).
Figure 2.2.1 shows an operation example of an external 0 interrupt, and Figure 2.2.2 shows a setting
example of an external 0 interrupt.
(2) External 1 interrupt
The INT1 pin is used for external 1 interrupt, of which valid waveforms can be chosen, which can
recognize the change of both edges (“H”
→
“L” or “L”
→
“H”).
Outline: An external 1 interrupt can be used by dealing with the change of edge (“H”
→
“L” or
“L”
→
“H”) in both directions as a trigger.
Specifications: An interrupt occurs by the change of an external signals edge (“H”
→
“L” or “L”
→
“H”).
Figure 2.2.3 shows an operation example of an external 1 interrupt, and Figure 2.2.4 shows a setting
example of an external 1 interrupt.
(3) Timer 1 interrupt
Constant period interrupts by a setting value to timer 1 can be used.
Outline: The constant period interrupts by the timer 1 underflow signal can be used.
Specifications: Prescaler and timer 1 divide the system clock frequency f(X
IN ) = 4.0 MHz, and the
timer 1 interrupt occurs every 1 ms.
Figure 2.2.5 shows a setting example of the timer 1 constant period interrupt.
(4) Timer 2 interrupt
Constant period interrupts by a setting value to timer 2 can be used.
Outline: The constant period interrupts by the timer 2 underflow signal can be used.
Specifications: Timer 2 divides the 16-bit fixed dividing frequency timer, and the timer 2 interrupt
occurs every about 2 sec.
Figure 2.2.6 shows a setting example of the timer 2 constant period interrupt.
(5) Timer 3 interrupt
Constant period interrupts by a setting value to timer 3 can be used.
Outline: The constant period interrupts by the timer 3 underflow signal can be used.
Specifications: Prescaler and timer 3 divide the system clock frequency f(X
IN ) = 4.0 MHz, and the
timer 3 interrupt occurs every 1 ms.
Figure 2.2.7 shows a setting example of the timer 3 constant period interrupt.