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CHAPTER 14 DTP/EXTERNAL INTERRUPT CIRCUIT
14.5 Operation of the DTP/External Interrupt Circuit
The DTP/external interrupt circuit provides the external interrupt function and the DTP
function. This section describes the settings required for each function and the
operation of the circuit.
s Setting the DTP/External Interrupt Circuit
Figure 14.5-1 "DTP/External Interrupt Circuit" shows the settings required to operate the DTP/
external interrupt circuit.
Figure 14.5-1 DTP/External Interrupt Circuit
Set the DTP/external interrupt circuit registers in accordance with the following procedure
because an interrupt request may be generated erroneously when setting them.
1. Set the DTP/interrupt enable register (ENIR) to "00H" to disable interrupt requests.
2. Set the interrupt detection condition to the external interrupt request detection condition
setting bit (LB7 to LB0, LA7 to LA0) corresponding to the external interrupt input pin (INT7 to
INT0) of the request level setting register (ELVR).
3. Set the external interrupt request flag bit (ER7 to ER0) corresponding to the external
interrupt input pin (INT7 to INT0) of the DTP/interrupt cause register (EIRR) to "0" to clear
the interrupt request.
4. To enable an interrupt request, set the external interrupt request enable bit (EN7 to EN0)
corresponding to the external interrupt input pin (INT7 to INT0) of the DTP/interrupt enable
register (ENIR) to "1".
ICS3 ICS2 ICS1 ICS0 ISE IL2
IL1 IL0
ICS3 ICS2 ICS1 ICS0 ISE IL2 IL1 IL0
0
1
0
1
For the external interrupt function
For the DTP function
ER7 ER6 ER5 ER4 ER3 ER2 ER1 ER0 EN7 EN6 EN5 EN4 EN3 EN2 EN1 EN0
ICR07(Upper)
/ICR08(Lower)
EIRR
/ENIR
ELVR
DDR1/DDR6
LB1 LA1 LB0 LA0
LB3 LA3 LB2 LA2
bit12 bit11
bit9
bit8
bit10
bit15 bit14 bit13
bit4 bit3
bit1
bit0
bit2
bit7
bit6 bit5
LB5 LA5 LB4 LA4
LB7 LA7 LB6 LA6
P63
P13 P12 P11 P10
P16 P15 P14
: Used
: Set the bit corresponding to the bit used to 1.
: Set the bit corresponding to the bit used to 0.
0 : Specifies 0.
1 : Specifies 1.
- : Unused bit