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(6)
Key return mode register 01 (KRM01) (
This register is used to set the pin that is to detect the key return signal (falling edge of port 6).
KRM01 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to 00H.
Symbol
7
6
KRM01 KRM017
KRM016
KRM010
0
Key return signal not detected
1
Key return signal detected (P60 to P63 falling edge detection)
KRM01n
0
Key return signal not detected
1
Key return signal detected (P6n falling edge detection)
Remark
n = 4 to 7
Cautions 1. Always set bits 1 to 3 to 0.
2. Before setting KRM01, set bit 5 of MK2 (KRMK01 = 1) to disable interrupts. To enable
interrupts, clear KRMK01 after clearing bit 5 of IF2 (KRIF01 = 0)
3. If any of the pins specified for key return signal detection is low level, the key return
signal cannot be detected even if a falling edge is generated at other key return pins.
4. When even one of the P60/ANI0/KR10 to P67/ANI7/KR17 pins is used as an A/D input, set
KRM010 and KRM014 to KRM017 to 0.
P60/ANI0/KR10
P61/ANI1/KR11
P62/ANI2/KR12
P63/ANI3/KR13
P64/ANI4/KR14
P65/ANI5/KR15
P66/ANI6/KR16
P67/ANI7/KR17
Note For selecting the pin to be used as falling edge input
300
CHAPTER 16 INTERRUPT FUNCTIONS
µ
PD789489, 78F9489 only)
Figure 16-8. Format of Key Return Mode Register 01
5
4
3
KRM015
KRM014
0
Control of key return signal detection
Control of key return signal detection
Figure 16-9. Block Diagram of Falling Edge Detector
Key return mode register 01
(KRM01)
User's Manual U15331EJ4V1UD
2
1
0
Address
0
0
KRM010
Falling edge detector
KRMK01
After reset
R/W
FFF4H
00H
R/W
INTKR01
Standby release
signal
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