First, context: I'm attempting to generate HDL code from a Simulink model, which includes a MATLAB Function block. The relevant function is:
function [output, valid] = demux(input)
demuxed = zeros(num_outputs, 1, 'like', input);
output = demuxed(1:num_outputs, 1);
In my Simulink model, both input and output are sfix24_En23 types (fixed-point, signed, 24 bits total, 23 bits fractional):
I've tried to hint to MATLAB that output should be fixed-point as well, even including this line at the beginning of the function:
output = fi(zeros(num_outputs, 1), true, 24, 23);
This explicitly includes my fixed-point parameters, which isn't great for maintainability, but would be acceptable for now in order to allow the model to compile.
However, in this and every other case I've tested, the Simulink console complains that Inferred type ('double') for data 'output' does not match back propagated type ('embedded.fi (sfix24_En23)') from Simulink. Is there a way to make MATLAB realize that the output isn't actually a double?
