What is the initial value of DFF if input is fed from output

[leongch]

hi,
i am trying to do the a frequency divider by 2 by using the DflipFlop
The design just simple where the output of the DflipFlop is feedback to input of the DFF... While i run the compilation the ALTERA QuartusII not allow the input to be feed directly from the output. Anyway to solve this kinda problem? Thanks
Oh... by VHDL ... [/img]

 

[Nandy]

You should add a revert before feedback the output. And you should reset the flipflop.

Nandy
www.nandigits.com
Netlist Debug/ECO in GUI mode.

 

[leongch]

ops...sorry, the feedback loop going to hv a inverter...
Nandy, just to clarify, do u mean, we first reset the flipflop first then the output will be LOW (0) can cause the input to be '1' ?

 

[Nandy]

Yes. You have to reset FF.
Otherwise you can't sim the circuit.

Nandy
www.nandigits.com
Netlist Debug/ECO in GUI mode.

 

[Resistance]

Re: What is the initial value of DFF if input is fed from ou

hi

Small error dude jus take it from QN and feed it back to D.. u will get it..

But getting to ur q : connect Q to D then it would be controlled by S and R pins..