Analog Devices Blackfin ADSP-BF537 Hardware Reference Manual page 861

General-Purpose Ports
A
EDGE
WRITE PORTxIO_EDGE TO SET
EDGE OR LEVEL
APPROPRIATE BITS FOR EDGE SENSITIVITY
SENSITIVE?
LEVEL
EDGE RISING/
WRITE PORTxIO_EDGE TO CLEAR RISING OR FALLING
FALLING OR BOTH?
APPROPRIATE BITS FOR LEVEL SENSITIVITY
BOTH
WRITE PORTxIO_BOTH TO SET
HIGH
LEVEL HIGH
APPROPRIATE BITS FOR BOTH EDGE SENSITIVITY
OR LOW?
LOW
WRITE PORTxIO_BOTH TO CLEAR APPROPRIATE
BITS FOR EDGE SENSITIVITY
WRITE PORTxIO_POLAR TO SET
APPROPRIATE BITS FOR LOW LEVEL SENSITIVITY
RISING
EDGE RISING
WRITE PORTxIO_POLAR TO CLEAR APPROPRIATE OR FALLING?
BITS FOR HIGH LEVEL SENSITIVITY
FALLING
WRITE PORTxIO_POLAR TO SET
APPROPRIATE BITS FOR FALLING EDGE SENSITIVITY
WRITE PORTxIO_POLAR TO CLEAR APPROPRIATE
BITS FOR RISING EDGE SENSITIVITY
SOFTWARE CAN INTERROGATE
NO
INTERRUPT
PORTx_DATA BITS TO
ABILITY?
DETERMINE EVENTS
YES
WRITE EITHER PORTxIO_MASKA, PORTxIO_MASKB, PORTxIO_MASKA_SET,
PORTxIO_MASKB_SET, PORTxIO_MASKA_TOGGLE, OR PORTxIO_MASKB_TOGGLE
TO SET APPROPRIATE BITS ON WHICH TO GENERATE AN INTERRUPT
INTERRUPTS MUST THEN BE CONFIGURED AT THE
SYSTEM INTERRUPT CONTROLLER AND
CORE EVENT CONTROLLER
Figure 14-8. GPIO Flow Chart (Part 2 of 2)
ADSP-BF537 Blackfin Processor Hardware Reference 14-21