Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 24 KEY INTERRUPT FUNCTION
R01UH0042EJ0500 Rev.5.00 Page 1305 of 1513
Aug 12, 2011
24.2 Register
(1) Key return mode register (KRM)
The KRM register controls the KRM0 to KRM7 bits using the KR0 to KR7 signals.
This register can be read or written in 8-bit or 1-bit units.
Reset sets this register to 00H.
KRM7
Does not detect key return signal
Detects key return signal
KRMn
0
1
Control of key return mode
KRM KRM6 KRM5 KRM4 KRM3 KRM2 KRM1 KRM0
After reset: 00H R/W Address: FFFFF300H
Caution Rewrite the KRM register after once setting the KRM register to 00H.
Remark For the alternate-function pin settings, see Table 4-20 Settings When Port Pins Are
Used for Alternate Functions.
24.3 Cautions
(1) If a low level is input to any of the KR0 to KR7 pins, the INTKR signal is not generated even if the falling edge of
another pin is input.
(2) If the KRM register is changed, an interrupt request signal (INTKR) may be generated. To prevent this, change the
KRM register after disabling interrupts (DI) or masking, then clear the interrupt request flag (KRIC.KRIF bit) to 0,
and enable interrupts (EI) or clear the mask.
(3) To use the key interrupt function, be sure to set the port pin to the key return pin and then enable the operation with
the KRM register. To switch from the key return pin to the port pin, disable the operation with the KRM register and
then set the port pin.