how to control the half of a port ?

[Salenko]

Hi ,

is there a built-in function to use , entirely, a half of a port as INPUT and the other half as OUTPUT, since output_x() or input_x() functions take the hole pins of the port.

I've found a solution for the input by using the '>>' or '<<' operators, but still not for the output.


I'm posting this question cause I need a solution to use the PortB for controlling my keypad (RB0-->RB3 for columns[outputs], RB4-->RB7 for Lines [inputs]),

I know that there is functions to control each port as output_bit(PIN_X,value) do, but this is not what I'm looking for, since I have to read or write 4 bits variables (which values are bytes)


any help ?

thanks.


Compiler PCW 4.057
PIC 16F876.

[SherpaDoug]

I think you are going to have to roll your own functions for this. Look at the often overlooked swap() function. It may be useful.
_________________
The search for better is endless. Instead simply find very good and get the job done.

[PCM programmer]

You have to use #fast_io on a split port, and set the TRIS. You also need
to define a structure with bitfields for each group of bits in the port.
Then you can define macros to provide an easy interface to the bitfields.

Note that all parameters and return values used in the macros are
right justified. The compiler handles bit shifting internally for you.
You don't have to worry about it.

Example:

[Salenko]

hi,
thank you very much for your support PCM