CHAPTER 14 INTERRUPT FUNCTIONS
Preliminary User’s Manual U16846EJ1V0UD
284
(4) External interrupt rising edge enable register (EGP), external interrupt falling edge enable register (EGN)
These registers specify the valid edge for INTP0 to INTP5.
EGP and EGN are set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears these registers to 00H.
Figure 14-5. 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
EGP5 EGP4 EGP3 EGP2 EGP1 EGP0
Address: FF49H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
EGN
0
0
EGN5 EGN4 EGN3 EGN2 EGN1 EGN0
EGPn
EGNn
INTPn pin valid edge selection (n = 0 to 5)
0
0
Edge detection disabled
0
1
Falling
edge
1
0
Rising
edge
1
1
Both rising and falling edges
Table 14-3 shows the ports corresponding to EGPn and EGNn.
Table 14-3. 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
EGP4 EGN4
P33
INTP4
EGP5 EGN5
P16
INTP5
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 5