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14.5 Operation of the DTP/External Interrupt Circuit
r Switching between the external interrupt function and the DTP function
Switching between the external interrupt function and the DTP function is set by the EI2OS
enable bit (ISE) of the interrupt control register (ICR) corresponding to the interrupt cause to be
used. When the EI2OS enable bit (ISE) is set to "1", the extended intelligent I/O service (EI2OS)
is enabled, operating as the DTP function. When the EI2OS enable bit (ISE) is set to "0", the
extended intelligent I/O service (EI2OS) is disabled, and the register operates as the external
interrupt function.
s Operation of the DTP/External Interrupt Circuit
The DTP/external interrupt circuit outputs an interrupt request to the interrupt controller when,
after operations are set to the request level setting register (ELVR), DTP/interrupt cause register
(EIRR), and DTP/interrupt enable register (ENIR), the detection condition set in the request
level setting register (ELVR) is input to the corresponding external interrupt input pin (INT7 to
INT0). When the EI2OS enable bit (ICR: ISE) of the interrupt control register is "0", interrupt
processing is performed. When the EI2OS enable bit (ICR: ISE) of the interrupt control register
is "1", interrupt processing is performed after the extended intelligent I/O service processing
(DTP processing) is executed.
Figure 14.5-2 DTP/External Interrupt Circuit
Table 14.5-1 Control Bit and Interrupt Cause of the DTP/External Interrupt Circuit
DTP/external interrupt circuit
External interrupt request flag bit
EIRR: ER7 to ER0
External interrupt request enable bit
ENIR: EN7 to EN0
Interrupt cause
Input of an effective edge or level to pin INT7 to INT0
ELVR
EIRR
ENIR
ICR YY
ICR XX
DTP/external interrupt circuit
Cause
CMP
IL
ILM
CMP
Interrupt processing
microprogram
Another request
Interrupt controller
CPU
INT7 to INT0
Pin
ELVR : Request level setting register
EIRR : DTP/interrupt cause register
ENIR : DTP/interrupt enable register
ICR
: Interrupt control register
IL
: Interrupt level setting bit of the interrupt control register (ICR)
ILM
: Interrupt level mask register in PS
CMP : Comparator