III - 47Chapter 3 InterruptsExternal Interrupts3-3-4 Programmable Active Edge Interrupt■Programmable Active Edge Interrupts (External interrupts 0 to 4)Through register settings, external interrupts 0 to 5 can generate interrupt at the selected edge eitherrising or falling edge.■Programmable Active Edge Interrupt Setup Example (External interrupt 0 to 4)External interrupt 4 (IRQ4) is generated at the rising edge of the input signal from P24.The table below provides a setup example for IRQ4.(1) Set the REDG4 flag of the external interrupt 4control register (IRQ4ICR) to "1" to specify therising edge as the active edge for interrupts.(2) Set the interrupt priority level in the IRQ4LV1-0flag of the IRQ4ICR register.If the interrupt request flag has been alreadyset, clear it.[ Chapter 3. 3-1-4 Interrupt flag setup ](3) Set the IRQ4IE flag of the IRQ4ICR register to"1" to enable the interrupt.Setup Procedure(1) Specify the interrupt active edge.IRQ4ICR (x'3FE6')bp5 : REDG4 = 1(2) Set the interrupt level.IRQ4ICR (x'3FE6')bp7-6 : IRQ4LV1-0= 10(3) Enable the interrupt.IRQ4ICR (x'3FE6')bp1 : IRQ4IE = 1DescriptionExternal interrupt 4 is generated at the rising edge of the input signal from P24.The Interrupt request flag can be set to "1" at switching the interrupt edge, so specify theinterrupt active edge before the interrupt permission.The external interrupt pin is recommended to be pull-up in advance.When the programmable active edge interrupt is specified for external interrupt 0 to 4 (IRQ0to IRQ4), set the EDGSELn flag of the both edge interrupt control register (EDGDT) to "0".
