NAME

       mux_generic - choose one from several input values

SYNOPSIS

       loadrt mux_generic config="bb8,fu12...."

FUNCTIONS

       mux-gen.NN  Depending on the data types can run in either a floating point or non-floating
       point thread.

PINS

       mux-gen.NN.suppress-no-input bit in
              This suppresses changing the output if all select  lines  are  false.   This  stops
              unwanted jumps in output between transitions of input but makes in00 unavailable.

       mux-gen.NN.debounce-us unsigned in
              sets  debouce  time  in  microseconds,  e.g.  100000  =  a  tenth of a second.  The
              selection inputs must be stable this long before the output changes.  This helps to
              ignore 'noisy' switches.

       mux-gen.NN.sel-bit-MM bit in (M=0..N)

       mux-gen.NN.sel-int unsigned in
              Together,  these  determine  which inN value is copied to output.  The bit pins are
              interpreted as binary bits, and the result is simply added on to  the  integer  pin
              input.   It  is  expected  that  either  one  or  the other would normally be used.
              However, the possibility exists to use a higher-order bit to "shift" the values set
              by the integer pin.  The sel-bit pins are only created when the size of the mux_gen
              component is an integer power of two.  This component (unlike mux16) does not offer
              the  option  of  decoding  Gray-code,  however  the  same effect can be achieved by
              arranging the order of the input values to suit.

       mux-gen.NN.out-[bit/float/s32/u32] variable-type out
              Follows the value of one of the inN values according to the selection  bits  and/or
              the  selection  number.  Values will be converted/truncated according to standard C
              rules.  This means, for example that a float input  greater  than  2147483647  will
              give an S32 output of -2147483648.

       mux-gen.NN.in-[bit/float/s32/u32]-MM variable-type in
              The possible output values that are selected by the selection pins.

PARAMETERS

       mux-gen.N.elapsed float r
              Current value of the internal debounce timer for debugging.

       mux-gen.N.selected s32 r
              Current  value  of  the internal selection variable after conversion for debugging.
              Possibly useful for setting up gray-code switches.

DESCRIPTION

       This component is a more general version of the other multiplexing components.  It  allows
       the  creation  of  arbitrary-size  multiplexers  (up  to  1024  entries) and also supports
       differing data types on the input and output pins.  The configuration string is  a  comma-
       separated list of code-letters and numbers, such as "bb4,fu12".
        This would create a 4-element bit-to-bit mux and a 12-element float-to-unsigned mux.  The
       code letters are b = bit, f = float, s = signed integer, u = unsigned integer.  The  first
       letter  code  is  the  input type, the second is the output type.  The codes are not case-
       sensitive. The order of the letters is significant but the position in the string is  not.
       Do not insert any spaces in the config string.  Any non-zero float value will be converted
       to a "true" output in bit form.  Be wary that float datatypes can be very, very, close  to
       zero and not actually be equal to zero.

       Each  mux  has  its own HAL function and must be added to a thread separately.  If neither
       input nor output is of type float then the function is  base-thread  (non  floating-point)
       safe.   Any  mux_generic  with  a  floating  point  input or output can only be added to a
       floating-point thread.

AUTHOR

       Andy Pugh

LICENSE

       GPL