how to create bit vector depending on another bit vector ?

hi, I have 20 bits in a vector (binary bits): for example, start from:

TMP_reg = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0];
TMP_reg = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1];
TMP_reg = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1];
..
..
end at:
TMP_reg = [1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1];

I want to produce another bits vector that depends on TMP_reg.

The new vector will be 40 bits vector on condition like that:

1. For every bit that equal to 1 in TMP_reg, the New_reg will be 1 0 (as long as TMP_reg bit is 1).
2. For every bit that equal to 0 in TMP_reg the New_reg will be 0 1 (as long as TMP_reg bit is 0).

Any suggestion how to do it?

Thanks,

Henry

[Steven Lord]

It's not clear what you're looking for. Let's take smaller examples.

What do you want New_reg to be for TMP_reg equal to [1 0 1 1 0 0] and why?

What do you want New_reg to be for TMP_reg equal to [1 1 1 1 1 1] and why?

What do you want New_reg to be for TMP_reg equal to [0 0 0 0 0 0] and why?

Answer 1

[Guillaume]

One possible way:

bitpatterns = {[0 1], [1 0]}; %in the order pattern for 0, pattern for 1
TMP_reg = [0 0 1 0 1 1 0]; %length does not matter
TMP_2 = cell2mat(bitpatterns(TMP_reg + 1)) %add 1 to TMP_reg to create indices 1 or 2 used to index bitpatterns

[Henry Buck]

It works.... :-))).

Thanks a lot.

Another issue is to creat TMP_reg. I have index input that runs from 0 to 20. In each stage of the index(runs from 0 to 20), I am changing TMP_reg manually: if index = 0 then TMP_reg=[0 0 0....0 0 1] if index = 1 then TMP_reg=[0 0 0....0 1 1] if index = 2 then TMP_reg=[0 0 0....1 1 1] .. .. if index = 19 then TMP_reg=[0 1 1....1 1 1] if index = 20 then TMP_reg=[1 1 1....1 1 1]

can I do it in better way ? I mean Automaticaly instead manually ?

Thanks a lot, Henry

[Guillaume]

Well, yes of course, it can be done. Either:

for index = 1:20 %can't run from 0 to 20, that's 21 bits
   TMP_reg = [zeros(20-index, 1), ones(index, 1)];
   %do something with it
end

Or even simpler:

TMP_allreg = flipud(triu(ones(20)));
for index = 1:20
   TMP_reg = TMP_allreg(index, :);
   %... do something with it
end

[Henry Buck]

great,

One thing I dont understand.... From command prompt/line it works perfect, but when I write it into file.m it does not work. how come ?

function gate_h = gate_array(I_H, indx_h)

if(I_H > 0)
        for indx_h=1:20
           TMP_reg = [zeros(1, 20-indx_h), ones(1, indx_h)]; 
        end
end

bitpatterns = {[0 1], [1 0]};
gate_h = cell2mat(bitpatterns(TMP_reg + 1));

the result is the same 40 bit output and does not change while the indx changing....

can you understand why ?

[Henry Buck]

hi,

I just change it in that way and it works.

But in simulink lots of error :

function gate_h = gate_array(I_H, indx_h)  
no_cells = 20;    
if(I_H > 0) 
    TMP_reg = [zeros(1, no_cells-indx_h), ones(1, indx_h)]; 
else 
    TMP_reg = [ones(1, indx_h), zeros(1, no_cells-indx_h)];
end  
bitpatterns = {[0 1], [1 0]};
gate_h = cell2mat(bitpatterns(TMP_reg + 1));

for example:

Component: Simulink | Category: N.A.

   Simulink does not have enough information to determine output sizes for
  this block. If you think the errors below are inaccurate, try specifying
  types for the block inputs and/or sizes for the block outputs.
  Component: MATLAB Function | Category: Coder error

   Cell arrays are not supported for code generation.

Function 'gate_array_h' (#130.645.659), line 20, column 15:
"{[0 1], [1 0]}"
Launch diagnostic report.
Component: MATLAB Function | Category: Coder error

   Undefined function or variable 'bitpatterns'. The first assignment to a local variable determines its class.

Function 'gate_array_h' (#130.679.690), line 21, column 19:
"bitpatterns"
Launch diagnostic report.
Component: MATLAB Function | Category: Coder error

   Errors occurred during parsing of MATLAB function 'gate_array_h'(#129)
  Component: MATLAB Function | Category: Coder error

   Error due to multiple causes.

Errors occurred during parsing of MATLAB function 'gate_array_h'(#129)

Error in port widths or dimensions. Output port 1 of 'untitled/gate_array_h/indx_h' is a one dimensional vector with 1 elements.
Component: Simulink | Category: Model error

Do you know how to solve it ?

Thanks, Henry

[Guillaume]

Why bother generating TMP_reg in your function if it's only a temporary variable? You may as well generate the final output directly:

function gate_h = gate_array(I_H, indx_h)
   gate_h = [repmat([1 0], 1, indx_h), repmat([0 1], 1, 20-indx_h)];
   if I_H > 0
     gate_h = fliplr(gate_h);
   end
end

This also avoids the cell array which appears to cause problem with Simulink.

I know nothing about Simulink, so no idea if it'll be happy with the above.

[Henry Buck]

Graet,

I will forward your answer(by your permition..) to someone who knows how to convert it into Simulink models, hopefully...