CHAPTER 16 INTERRUPT FUNCTIONS
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User’s Manual U15331EJ4V1UD
(6) Key return mode register 01 (KRM01) (
µ
PD789489, 78F9489 only)
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.
Figure 16-8. Format of Key Return Mode Register 01
Symbol
7 6 5 4 3 2 1 0
Address
After
reset
R/W
KRM01 KRM017 KRM016 KRM015 KRM014
0
0
0
KRM010
FFF4H
00H
R/W
KRM010
Control of key return signal detection
0
Key return signal not detected
1
Key return signal detected (P60 to P63 falling edge detection)
KRM01n
Control of key return signal detection
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.
Figure 16-9. Block Diagram of Falling Edge Detector
P60/ANI0/KR10
P61/ANI1/KR11
P62/ANI2/KR12
P63/ANI3/KR13
P64/ANI4/KR14
P65/ANI5/KR15
P66/ANI6/KR16
P67/ANI7/KR17
KRMK01
INTKR01
Falling edge detector
Standby release
signal
Key return mode register 01
(KRM01)
Selector
Note
Note
For selecting the pin to be used as falling edge input
Содержание PD789488
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