Fujitsu MB90420/5 (A) Series Hardware Manual page 392

• Precautions for interrupts
Control cannot be return from the interrupt processing when the external interrupt request flag bit is 1 and
the interrupt request output is still enabled when the external interrupt function is used. Consequently,
always clear the external interrupt request flag bit inside the interrupt-processing routine (The bit is cleared
automatically by the EI
the level that becomes the interrupt factor remains input, the external interrupt request flag bit is reset
immediately even when cleared. Disable the interrupt request output as needed, or cancel the interrupt
factor itself.
• CAN WAKEUP function
The CAN WAKEUP function switches between the INT0 pin connection and the RX pin connection
internally. Consequently, when the CAN WAKEUP function is used, the INT0 function cannot be used.
DTP/EXTERNAL INTERRUPT CIRCUIT
2
OS when the DTP function is used). Also, when the setting is level detection and
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