interrupt. Neither of these flags is cleared by hardware when the service routine is vectored to.
The service routine should poll them to determine which one to request service and it will be
cleared by software.
All of the bits that generate interrupts can be set or cleared by software with the same result
as done through it by hardware. In other words, interrupts or pending interrupts can be
generated or canceled in software.
The following content describes several SFR related to interrupt mechanism.
SFR: IE (Interrupt Enable)
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
EA
EPCA_LVD ESPI_ADC
ES
ET1
EX1
ET0
EX0
EA:=Global interrupt controller.
0:=(default)
Disable all interrupts
1:=
Release interrupt control to all individual interrupt controllers.
EPCA_LVD:=Interrupt controller of Programmable Counter Array (PCA) and Low-Voltage
Detector
0:=(default)
Disable
1:=
Enable
ESPI_ADC:=Interrupt controller of Serial Peripheral Interface (SPI) and A/D Converter (ADC).
0:=(default)
Disable
1:=
Enable
ES:=Interrupt controller of Universal Asynchronous Receiver/Transmitter (UART).
0:=(default)
Disable
1:=
Enable
ET1:=Interrupt controller of Timer-1 interrupt.
0:=(default)
Disable
1:=
Enable
EX1:=Interrupt controller of external interrupt-1.
0:=(default)
Disable
1:=
Enable
30
MPC82x54A Data Sheet
MEGAWIN