Description of Operation
9-18
ADSP-BF50x Blackfin Processor Hardware Reference
When the GPIO’s input drivers are enabled while the GPIO direction reg-
isters configure it as an output, software can trigger a GPIO interrupt by
writing to the data/set/toggle registers. The interrupt service routine
should clear the GPIO to acknowledge the request.
Each of the three GPIO modules provides two independent interrupt
channels. Identical in functionality, these are called interrupt A and inter-
rupt B. Both interrupt channels have their own mask register which lets
you assign the individual GPIOs to none, either, or both interrupt
channels.
Since all mask registers reset to zero, none of the GPIOs is assigned any
interrupt by default. Each GPIO represents a bit in each of these registers.
Setting a bit means enabling the interrupt on this channel.
Interrupt A and interrupt B operate independently. For example, writing
1 to a bit in the mask interrupt A register does not affect interrupt channel
B. This facility allows GPIOs to generate GPIO interrupt A, GPIO inter-
rupt B, both GPIO interrupts A and B, or neither.
A GPIO interrupt is generated by a logical OR of all unmasked GPIOs for
that interrupt. For example, if
PF0
and
PF1
are both unmasked for GPIO
interrupt channel A, GPIO interrupt A will be generated when triggered
by
PF0
or
PF1
. The interrupt service routine must evaluate the GPIO data
register to determine the signaling interrupt source.
Figure 9-1
illustrates
the interrupt flow of any GPIO module's interrupt A channel.
When using either rising or falling edge-triggered interrupts, the
interrupt condition must be cleared each time a corresponding
interrupt is serviced by writing 1 to the appropriate bit in the
GPIO clear register.
At reset, all interrupts are masked and disabled.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...