D Flip flop using matlab code(not simulink)

I wrote a function to implement d flip flip (using nand gates and hence used the ~(a&b)operation in matlab) .I get an error during execution of my function.What caused it and how do I fix it?

[x,y] = dflipflop(1101101101,1010101010)
Unrecognized function or variable 'q1'.

Error in dflipflop (line 9)
g4 = ~(g1 & q1);

This is the function:

function [Q1,q1] = dflipflop(d,clk)
%dflipflop Summary of this function goes here
%   Detailed explanation goes here
% Q1 = d;
% q1 = clk;
g1 = ~(d & clk);
d_not = not(d);
g3 = ~(clk & d_not);
g4 = ~(g1 & q1);
g5 = ~(g3 & Q1);
Q1= g4;
q1 = g5;

end

The circuit diagram that I tried to realize is:

I am using MATLAB Online version.

I needed to use the output q1(from previous stage) to calculate the present output.I actally want to input signals(digital) to the flipflop unit .Is there a way of doing the same?

I am fairly new to Matlab.

[Rafael Hernandez-Walls]

In this line:

g4 = ~(g1 & q1);

You need to declare before the variable q1

Answer 1

[Sulaymon Eshkabilov]

Hi,

Here is the fixed code:

[x,y] = dflipflop(1101101101,1010101010)

function [Q1,q1] = dflipflop(d,clk)
%dflipflop Summary of this function goes here
%   Detailed explanation goes here
% Q1 = d;
% q1 = clk;
g1 = ~(d & clk);
d_not = not(d);
g3 = ~(clk & d_not);
g4 = ~(g1 & g1);
g5 = ~(g3 & g4);
Q1= g4;
q1 = g5;

end

[V V arfitha]

Actally i needed to use the output q1(from previous stage) to calculate the present output.so i think g4 = ~(g1 & g1); this may not be the correct logic.

In such cases do we need to use recurrsive function?