Ho we run a section code one time in Matlab function block ? In below body I dont want assigning zeros in Dout after 1st iteration. This matlab function block run 100 times and problem is it every time set zeros in dout.

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Sarfaraz Ahmed 2018-10-2

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编辑： Sarfaraz Ahmed 2018-10-6

function y = ADC(u, clk, count)
%function y = fcn(u, clk)
count=count+1;
% if clk==1
%     disp('hello');
% end
% emulation of SAR ADC operation
Nbit = 7; 
Vref = 64;
VCM = Vref/2;
%dVin = (-37298:37299)/37299*Vref;
Point=u;
dVin = (-Point:Point)/Point*Vref;
%plot(dVin);
Vip = dVin/2+VCM;
Vin = -dVin/2+VCM;
N = length(dVin);
k=count;
*Dout = zeros(1,N);
B = zeros(1,Nbit);*
   while k <=N          
          if clk==1
              Vxp = Vip(k);
              Vxn = Vin(k);
              for kbit = 1:Nbit
                  if Vxp - Vxn > 0
                      B(kbit) = 1;
                      Vxp = Vxp - Vref*2^(-kbit);
                  else
                      B(kbit) = 0;
                      Vxn = Vxn - Vref*2^(-kbit);
                  end
              end
              Dout(k) = B(1)*64 + B(2)*32 + B(3)*16 + B(4)*8 + B(5)*4 + B(6)*2 + B(7)*1 -64 +0.5;
            %  k=k+1;
             break;
          else
             %k=k+1;
             break
          end
      end
plot(dVin,Dout,'r*')
y = Dout;

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Honglei Chen 2018-10-2

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You can make Dout persistent so it preserves the value between runs, like this

persistent Dout;
if isempty(Dout)
  Dout = zeros(1,N);
end

HTH

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Walter Roberson 2018-10-5

You should be using a triggered subsystem if the code is not to run at all when the control signal is 0.

Note: in such a case you would no longer need clk1 as an input, as the reconfigured block would only get run when clk1 was 1.

Sarfaraz Ahmed 2018-10-6

编辑：Sarfaraz Ahmed 2018-10-6

Thanks. Let me use triggered system.

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Honglei Chen 2018-10-5

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Do you get an error? What is the error message? Looks like you may have some dimension issues? An alternative way is to control the calling of this block, like in a subsystem so it does not get triggered when clock is 0.

HTH

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Walter Roberson 2018-10-6

The clock is a signal. You can put a delay block on the signal. Or you could use a pulse generator such as https://www.mathworks.com/help/simulink/slref/pulsegenerator.html

Sarfaraz Ahmed 2018-10-6

编辑：Sarfaraz Ahmed 2018-10-6

在 MATLAB Online 中打开

Thanks. I am using this with delay but no effect it sample at same time. how can I do this so that it sample according to clock delay. I think the clock is not properly time based . I attached a snap please have a look and my sampler code below:

function Vin = sample(ip) coder.extrinsic('stem');

persistent x1;

if isempty(x1) % Initialization x1=0; end

persistent M;

if isempty(M) % Initialization M=1; end

% Sampling input signal1

f=10e3; %Frequency of sinusoid nCyl=5; %generate five cycles of sinusoid %(0:2^-6:5^-4) fs1=50e3; %50kHz sampling rate t1=0:1/fs1:nCyl*1/f; %time index size= length(t1);

%if clk1==1

    while M<=size
          x1=sin(2*pi*f*t1(M));
          stem(t1(M),x1);  % plotting discrete samples on the input signal1  
          M=M+1;              
          break;         
    end

%end

Vin=x1;

what if I use "pulstran" function and embed in subblock ? but when i use this function it shows an error "Function output 'y' cannot be an mxArray in this context. Consider preinitializing the output variable with a known type." The code for pulse is :

function y = pulse() coder.extrinsic('pulstran');

t=0:0.01:10; %Time vector w = 1; %pulse width d= w/2:w*2:10; %delay vector y2=pulstran(t,d,'rectpuls',w); subplot(2,1,1); plot(t,y2); set(gca,'Ylim',[-0.1 1.1]); xlabel('Time(s)');

y=y2;

I want it sample whenever clock pusle at the rising edge so when it with delays it should sample with delay. Please help me in this regard. Thanks

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