title: VHDL - Does not match a standard flipflop
body: <p>Im trying to program something pretty easy with "VHDL". But Im stuck with it for a few hours already and I cant find a way to make it work.</p>
  
  <p>Im trying to find a way to use the same signal in different process or combine them into one process.
  Using a signal in different processes is not possible and if I combine them into one process I get the error "Does not match a standard flipflop". I hope anyone here can help me out and say how I can fix this. </p>
  
  <p>Example code;</p>
  
  <pre><code>process(scan_ready,rc5_ready) 
  variable welkescan : std_logic_vector(1 downto 0);
  begin
      if (scan_ready' event and scan_ready = '0') and not((rc5_ready' event and rc5_ready = '0')) then
        welkescan := "01";
        visualisatiegebruikt &lt;= "0001";
        visualisatiecode &lt;= scan_code;
      elsif (rc5_ready' event and rc5_ready = '0') and not((scan_ready' event and scan_ready = '0')) then
        welkescan := "10";
        visualisatiegebruikt &lt;= "0010";
        visualisatiecode &lt;= scan_con;
      else
        welkescan := "00";
      end if;
  
      if ((welkescan = "01" and scan_code = "01110010") or (welkescan = "10" and scan_code = "00100001")) and (pwm_on /= "11111100") then
        pwm_on &lt;= pwm_on +  28;
        visualisatiepwm &lt;= visualisatiepwm + "0001";
      elsif ((welkescan = "01" and scan_code = "01110101") or (welkescan = "10" and scan_code = "00100000")) and (pwm_on /= "00000000") then
        pwm_on &lt;= pwm_on - 28;
        visualisatiepwm &lt;= visualisatiepwm - "0001";
      end if;
  end process;    
  </code></pre>
  
  <p>What I also tried Code example:</p>
  
  <pre><code>process(scan_ready)
  begin
      if scan_ready' event and scan_ready = '0' then
          visualisatie &lt;= "0001"; -- 1 op display =&gt; toetsenbord
          scanwaarde(3 downto 0) &lt;= scan_code(3 downto 0);
          scanwaarde(7 downto 4) &lt;= scan_code(7 downto 4);
          if scan_code = "01110010" and pwmaansturen /= "11111100" then 
              pwmaansturen &lt;= pwmaansturen +  28;
              visualisatiepwm &lt;= visualisatie + "0001";
          elsif scan_code = "01110101" and pwmaansturen /= "00000000" then
              pwmaansturen &lt;= pwmaansturen - 28;
              visualisatiepwm &lt;= visualisatie - "0001";
          elsif scan_code = "01110100" then
              pwmaansturen &lt;= "11111100";
              visualisatiepwm &lt;= "1001";
          elsif scan_code = "01101011" then
              pwmaansturen &lt;= "00000000";
              visualisatiepwm &lt;= "0000";
          end if;
      end if;
  end process;    
  
  process(rc5_ready) 
      begin
  
      if rc5_ready' event and rc5_ready = '0' then
          visualisatie &lt;= "0010"; -- 2 op display =&gt; afstandsbediening
          scanwaarde(3 downto 0) &lt;= scan_con(3 downto 0);
          scanwaarde(7 downto 4) &lt;= scan_con(7 downto 4);
          if scan_con = "00100001" and pwmaansturen /= "11111100" then 
              pwmaansturen &lt;= pwmaansturen + 28;
              visualisatiepwm &lt;= visualisatie + "0001";
          elsif scan_con = "00100000" and pwmaansturen /= "00000000" then 
              pwmaansturen &lt;= pwmaansturen - 28;
              visualisatiepwm &lt;= visualisatie - "0001";
          elsif scan_con = "00010110" then
              pwmaansturen &lt;= "11111100";
              visualisatiepwm &lt;= "1001";
          elsif scan_con = "00010111" then
              pwmaansturen &lt;= "00000000";
              visualisatiepwm &lt;= "0000";
          end if;
      end if;
  end process;
  </code></pre>
  
  <p>I hope that someone can help me.
  Greetings. </p>