i want to divide the o/p freq of Quad-VCO i.e. 4.8 GHz into 2.4 GHz. for this purpose i need a freq divider ckt.
i saw the freq divider from RF library in cadence. it is containing 4 pins (pin, pout,nin, nout).
how to apply stimulus to this pins & check the o/p
i dont know what nout stands for here
pin might be i/p power, pout might be o/p power
nin might be divide no.
Ask your supervisor?
Seriously, do you think there is anywhere enough information in your question for anyone to be able to give a sensible answer? You have given no clue what "pin, pout, nin and nout" pins are, or what it is you're actually trying to find about the divider. Are you interested in whether it functionally works, what the rise time of the edges are, the noise performance, distortion - you could be asking anything.
As explained in the Forum Guidelines, asking a specific and bounded question is much more likely to get an answer. Maybe if you read them and supply sufficient information, somebody can answer you.
i have figured it out they are differential i/p & o/p pins
But when i try to open the block (by pressing q) in CDF parameter view i choose veriloga view & fill all the parameters such as n,VDD,VSS,nhi,dir,tt etc (i.e. all the parameters in the code) & try to simulate it by doing transient analysis then i am getting o/p as 0(straight line) on both the pins
Are there any changes while simulating the veriloga code or we cannot use that block in schematic view ??????
I have entered the Simulator stop view list as spectre veriloga ...........
Still its not working......
Thanks in advance......
In reply to ddis:
Most likely you have tt set to too large a value (or left blank). The default value of tt is 0.01 seconds (which is rather long, so the output probably doesn't change unless you have a very slow clock).
I had the following parameters:
n=8nhi=2 # output will be two pulses of the input pulse widedir=1tt=1nvdd=1.2vss=0thresh=0.6 # this will be the default since it is (vdd+vss)/2.
I had this connected to a vsource in "pulse" mode with:
Zero value: 0One value: 1.2Period of waveform: 1uRise time: 1nFall time: 1nPulse width: 500n
Attached is a picture. This works exactly as you'd expect.
In reply to Andrew Beckett:
thanks a lot Andrew..
i have a doubt....
does it work only for input as pulse??
cant we give sine wave as input
I want to divide the VCO output by 2 & VCO's o/p is sine wave.
Yes, it works. Did you try? Provided you've got the threshold right - it simply looks when the threshold is crossed and uses that.
Look in the veriloga code - it's fairly clear what it is doing, and there are comments at the top.
it works for a sine wave by setting proper threshold but the o/p is a pulse....