BL4S200 User’s Manual
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3.2.1.3 Configurable I/O Special Uses
Individual configurable I/O pins may be used for interrupts, input capture, as quadrature
decoders, or as PWM outputs. The use of these channels for PWM, interrupts, input cap-
ture, and as quadrature decoders is described in the
Rabbit RIO User’s Manual
.
Blocks of configurable I/O pins are associated with counters/timers on the three Rabbit RIO
chips that support them. Table 5 provides complete details for these associations.
Configurable I/O pins DIO30 and DIO31 fully support all input-associated special uses
such as interrupts and input captures, but otherwise they are limited to function only as
regular digital I/O pins because their outputs are latch-driven since sufficient Rabbit RIO
resources are not available to support their use for specialized outputs.
Appendix D provides further details on the blocks and pins associated with each Rabbit
RIO chip to facilitate configuring each block consistently and to identify misconfigured
pins when a software function call returns a
Mode Conflict
error code.
Table 5. Counter/Timer Associations for BL4S200 Configurable I/O Pins
Configurable I/O
Pin(s)
Counter/Timer
Blocks
RIO Chip Index
DIO0–DIO3
4 (outputs)
5 (inputs)
0 (U8)
DIO4–DIO7
0 (outputs)
1 (inputs)
1 (U7)
DIO8–DIO11
2 (outputs)
3 (inputs)
1 (U7)
DIO12–DIO15
4 (outputs)
5 (inputs)
1 (U7)
DIO16–DIO17
0 (I/O)
2 (U9)
DIO18–DIO19
1 (I/O)
2 (U9)
DIO20–DIO21
2 (I/O)
2 (U9)
DIO22–DIO23
3 (I/O)
2 (U9)
DIO24–DIO25
4 (I/O)
2 (U9)
DIO26–DIO27
5 (I/O)
2 (U9)
DIO28
6 (output)
7 (input)
0 (U8)
DIO29
6 (output)
7 (input)
1 (U7)
DIO30
6 (input only)
2 (U9)
DIO31
7 (input only)
2 (U9)