Renesas 4513 Network Card User Manual


 
APPLICATION
2.2 Interrupts
2-18
4513/4514 Group User’s Manual
Fig. 2.2.2 INT0 interrupt setting example
Note: The valid waveforms causing the interrupt must be retained at their level for 4 cycles or more
of system clock.
Set Port
Port used for INT0 interrupt is set to input port.
0
b3 b0
b3 b0
1
✕✕
Both edges detection selected (TI1A instruction)
b3 b0
1
1
b3 b0
Disable Interrupts
INT0 interrupt is temporarily disabled.
Interrupt enable flag INTE
Interrupt control register V1
“0”
✕✕
All interrupts disabled (DI instruction)
INT0 interrupt occurrence disabled
(TV1A instruction)
Port P30 output latch
✕✕✕
Set to input (OP3A instruction)
Set Valid Waveform
Valid waveform of INT pin is selected.
Both edges detection selected
Interrupt control register I1
Clear Interrupt Request
External interrupt activated condition is cleared.
INT0 interrupt request flag EXF0
“0”
INT0 interrupt activated condition cleared
(SNZ0 instruction)
Note when the interrupt request is cleared
When is executed, considering the skip of the next instruction according to the
interrupt request flag EXF0, insert the NOP instruction after the SNZ0 instruction.
Enable Interrupts
The INT0 interrupt which is temporarily disabled is enabled.
Interrupt control register V1
Interrupt enable flag INTE
“1”
✕✕✕
INT0 interrupt occurrence enabled
(TV1A instruction)
All interrupts enabled (EI instruction)
INT0 interrupt execution started
”: it can be “0” or “1.”