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CHAPTER 15 INTERRUPT FUNCTIONS
Preliminary User’s Manual U16035EJ1V0UM
(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 input sets these registers to 00H.
Figure 15-5.
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
Interrupt disabled
0
1
Falling edge
1
0
Rising edge
1
1
Both rising and falling edges
(5) Memory expansion mode register (MEM)
MEM sets the rising edge detection function of port 4.
MEM is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets MEM to 00H.
Figure 15-6. Format of Memory Expansion Mode Register (MEM)
Address: FF47H After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
MEM
0
0
0
0
0
MM2
MM1
MM0
MM2
MM1
MM0
Single-chip/memory expansion mode selection
0
0
0
Single-chip mode
0
0
1
Port 4 falling edge detection mode
Other than above
Setting prohibited
Caution
When using the falling edge detection function of port 4, be sure to set MEM to 01H.