26
4513/4514 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
PRELIMINARY
Notice: This is not a final specification.
change.
Some parametric limits are subject to
(3) External interrupt control registers
Interrupt control register I1
Register I1 controls the valid waveform for the external 0 inter-
rupt. 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.
Interrupt control register I2
Register I2 controls the valid waveform for the external 1 inter-
rupt. 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.
Table 8 External interrupt control registers
I1
3
I1
2
I1
1
I1
0
I2
3
I2
2
I2
1
I2
0
Not used
Interrupt valid waveform for INT0 pin/
return level selection bit (Note 2)
INT0 pin edge detection circuit control bit
INT0 pin
timer 1 control enable bit
This bit has no function, but read/write is enabled.
Falling waveform (“L” level of INT1 pin is recognized with the SNZI1
instruction)/“L” level
Rising waveform (“H” level of INT1 pin is recognized with the SNZI1
instruction)/“H” level
One-sided edge detected
Both edges detected
Disabled
Enabled
Not used
Interrupt valid waveform for INT1 pin/
return level selection bit (Note 3)
INT1 pin edge detection circuit control bit
INT1 pin
timer 3 control enable bit
Notes 1: “R” represents read enabled, and “W” represents write enabled.
2: When the contents of I1
2
is changed, the external interrupt request flag EXF0 may be set. Accordingly, clear EXF0 flag with the SNZ0 instruction.
3: When the contents of I2
2
is changed, the external interrupt request flag EXF1 may be set. Accordingly, clear EXF1 flag with the SNZ1 instruction.
Interrupt control register I1
R/W
at RAM back-up : state retained
at reset : 0000
2
This bit has no function, but read/write is 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
Disabled
Enabled
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Interrupt control register I2
R/W
at RAM back-up : state retained
at reset : 0000
2