CHAPTER 13 INTERRUPT FUNCTIONS
Preliminary User’s Manual U19014EJ1V0UD
400
(4) External interrupt rising edge enable register (EGP), external interrupt falling edge enable register (EGN)
These registers specify the valid edge for INTP0 to INTP3.
EGP and EGN are set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets these registers to 00H.
Figure 13-5. Format of External Interrupt Rising Edge Enable Register (EGP)
and External Interrupt Falling Edge Enable Register (EGN)
Address: FF48H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
EGP
0 0 0 0
EGP3
EGP2
EGP1
EGP0
Address: FF49H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
EGN
0 0 0 0
EGN3
EGN2
EGN1
EGN0
EGPn
EGNn
INTPn pin valid edge selection (n = 0 to 3)
0
0
Edge detection disabled
0
1
Falling
edge
1
0
Rising
edge
1
1
Both rising and falling edges
Caution Be sure to clear bits 4 to 7 to 0.
Table 13-3 shows the ports corresponding to EGPn and EGNn.
Table 13-3. Ports Corresponding to EGPn and EGNn
Detection Enable Register
Edge Detection Port
Interrupt Request Signal
EGP0 EGN0
P120
INTP0
EGP1 EGN1
P30
INTP1
EGP2 EGN2
P31
INTP2
EGP3 EGN3
P32
INTP3
Caution Select the port mode by clearing EGPn and EGNn to 0 because an edge may be
detected when the external interrupt function is switched to the port function.
Remark
n = 0 to 3
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