Configuring a port as output using lib_xcore Topic is solved

[michaelf]

I'm just trying to translate a piece of code from XC to C, and I would like to confirm some functionality when configuring a port.

XC code:

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buffered out port:32 buffered_output_port = /* port */;

C code so far:

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port_t buffered_output_port = /* port */;
port.start_buffered(buffered_output_port, 32);
// how can I now change it from an "in" port (as is the default) to an "out" port?

I see that there is a function

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port_set_inout_data

, but the docs are ambiguous (I think there's a missing word):

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inline void port_set_inout_data(port_t __p)
Set a port drive out the data value (default state).

Parameters:
__p – Port to change the mode of.

.

Does called "set_port_inout_data(port)" set the port as an output port?

[xhuw]

hey, `port_set_inout_data` sets the port to "DATAPORT" mode, i.e. normal operation. This does nothing unless you have previously called `port_set_out_clock` or `port_set_out_ready` as "DATAPORT" is the default mode.

More on this in section 15.2 from the architecture manual https://www.xmos.com/download/The-XMOS- ... ecture.pdf

how can I now change it from an "in" port (as is the default) to an "out" port?

Use the `port_out` or `port_out_at_time` functions from <xcore/port.h>

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port_t buffered_output_port = /* port */;
port_start_buffered(buffered_output_port, 32);
port_out(buffered_output_port, 0);