SIC63616-(Rev. 1.0) NO. P59
3240-0412
NRSP01, NRSP00: Key input interrupt 0–3 noise reject frequency select register (FF11H•D1, D0)
NRSP11, NRSP10: Key input interrupt 4–7 noise reject frequency select register (FF11H•D3, D2)
Selects the noise reject frequency for the key input interrupts.
Table 4.5.8.2 Setting up noise rejector
NRSP01
NRSP11
1
1
0
0
Noise reject frequency
f
OSC1
/ 256 (128 Hz)
f
OSC1
/ 64 (512 Hz)
f
OSC1
/ 16 (2 kHz)
OFF
(bypassed)
NRSP00
NRSP10
1
0
1
0
Reject pulse width
7.8 msec
2.0 msec
0.5 msec
–
NRSP0x and NRSP1x are the noise reject frequency select registers that correspond to the key input interrupts
0–3 (P10–P13) and the key input interrupts 4–7 (P40–P43), respectively.
At initial reset, these registers are set to "00B".
EIK00–EIK03: Key input interrupt 0–3 mask register (FFEBH)
EIK10–EIK13: Key input interrupt 4–7 mask register (FFECH)
Enable/disable the key input interrupts.
When "1" is written: Enable
When "0" is written: Mask
Reading: Valid
EIK0x and EIK1x are the interrupt mask registers that correspond to the key input interrupts 0–3 (P10–P13)
and the key input interrupts 4–7 (P40–P43), respectively.
Setting EIKxx to "1" enables the interrupt and setting EIKxx to "0" disables the interrupt.
The SLEEP cancellation signal will be generated even if this register is set to "0". However, enable the key
input interrupt using the corresponding interrupt mask register before executing the SLP instruction to
execute the key input interrupt handler routine after SLEEP status is released.
At initial reset, these registers are set to "0".
IK00–IK03: Key input interrupt 0–3 factor flag (FFFBH)
IK10–IK13: Key input interrupt 4–7 factor flag (FFFCH)
These flags indicate the occurrence of key input interrupts.
When "1" is read:
Interrupt has occurred
When "0" is read:
Interrupt has not occurred
When "1" is written: Flag reset
When "0" is written: Invalid
The interrupt factor flags IK00–IK03 and IK10–IK13 are associated with the key input interrupts 0–3 (P10
–P13) and the key input interrupts 4–7 (P40–P43), respectively. From the status of these flags, the software
can decide whether an key input interrupt has occurred.
The interrupt factor flag is set to "1" when the interrupt condition is established regardless of the interrupt
mask register setting. However, the interrupt does not occur to the CPU when the interrupt is masked.
These flags are reset to "0" by writing "1" to them.
After an interrupt occurs, the same interrupt will occur again if the interrupt enabled state (I flag = "1") is
set or the RETI instruction is executed unless the interrupt factor flag is reset. Therefore, be sure to reset (write
"1" to) the interrupt factor flag in the interrupt service routine before shifting to the interrupt enabled state.
At initial reset, these flags are set to "0".