Rev.1.02
REJ03B0179-0102
May 25, 2007
Page 23 of 124
4571 Group
(3) External interrupt control registers
(1) Interrupt control register I1
Register I1 controls the valid waveform for the external 0
interrupt. Set the contents of this register through register A
with the TI1A instruction. The TAI1 instruction can be used
to transfer the contents of register I1 to register A.
(2) Interrupt control register I2
Register I2 controls the valid waveform for the external 1
interrupt. Set the contents of this register through register A
with the TI2A instruction. The TAI2 instruction can be used
to transfer the contents of register I2 to register A.
Note 1.“R” represents read enabled, and “W” represents write enabled.
Note 2.When the contents of I1
2
and I1
3
are changed, the external interrupt request flag EXF0 may be set.
Note 3.When the contents of I2
2
and I2
3
are changed, the external interrupt request flag EXF1 may be set.
Table 15 External interrupt control register
Interrupt control register I1
at reset : 0000
2
at RAM back-up : state retained
R/W
TAI1/TI1A
I1
3
INT0 pin input control bit (Note 2)
0
1
INT0 pin input disabled
INT0 pin input enabled
Falling waveform (“L” level of INT0 pin is recognized with the SNZI0
instruction)/“L” level
Rising waveform (“H” level of INT0 pin is recognized with the SNZI0
instruction)/“H” level
One-sided edge detected
Both edges detected
Timer 1 disabled
Timer 1 enabled
I1
2
Interrupt valid waveform for INT0 pin/
return level selection bit (Note 2)
0
1
I1
1
INT0 pin edge detection circuit control bit
0
1
0
1
I1
0
INT0 pin
timer 1 control enable bit
Interrupt control register I2
at reset : 0000
2
at RAM back-up : state retained
R/W
TAI2/TI2A
I2
3
INT1 pin input control bit (Note 3)
0
1
INT0 pin input disabled
INT0 pin input enabled
Falling waveform (“L” level of INT0 pin is recognized with the SNZI1
instruction)/“L” level
Rising waveform (“H” level of INT0 pin is recognized with the SNZI1
instruction)/“H” level
One-sided edge detected
Both edges detected
I2
2
Interrupt valid waveform for INT1 pin/
return level selection bit (Note 3)
0
1
I2
1
INT1 pin edge detection circuit control bit
0
1
0
1
I2
0
Not used
This bit has no function, but read/write is enabled.