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  1. #1
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    How to change the m factor (multiplication factor) for Instances in cadence

    Hello,

    I am using Cadence Virtuoso IC6.1.5 64 bit.

    In my design I have analog and digital parallel in-parallel out shift register. I need to fill this register with binary data.

    I am using Verilog to generate my digital data bits by designing functional block and put it in my simulation test bench, then I use to run simulation and set the simulator to 'AMS'.

    This configuration is not supporting all the simulations as spectra offers.

    The second thing is that I need to write Verilog code every time I need different type of data.

    Therefore I would like to ask you please if there is other option provided by cadence to generate pattern of parallel bits (that has configurable times and voltage) which can run under Spectra simulation

    Click image for larger version. 

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    Thank you

    Best Regards

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  2. #2
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    Re: How to change the m factor (multiplication factor) for Instances in cadence

    Quote Originally Posted by Junus2012 View Post
    How to change the m factor (multiplication factor) for Instances in cadence
    Depends on how you want the multiplication be done:

    Either m equal instances of the same device, then instantiate this device <1:m> times in parallel. Or you can multiply it by its Number of Gates, then enter the m value in the corresponding input window of the instance CDF symbol.


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  3. #3
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    Re: How to change the m factor (multiplication factor) for Instances in cadence

    Quote Originally Posted by erikl View Post
    Depends on how you want the multiplication be done:

    Either m equal instances of the same device, then instantiate this device <1:m> times in parallel. Or you can multiply it by its Number of Gates, then enter the m value in the corresponding input window of the instance CDF symbol.
    Dear Erikel
    Thank you for your help

    I need the variable (m), because I want to use the array matching generator by using Modgen from Cadence, with this variable the software can arrange the transistor in common centroid like AB/BA. If I use the number of gates rather, as a aration it is the same but for Modgen he will consider it as one transistor so he can only make AB.

    Thank you once again



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    Re: How to change the m factor (multiplication factor) for Instances in cadence

    Your PDK doesn't support multiplier parameter. You have to instantiate as vector as erikl said.



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    Re: How to change the m factor (multiplication factor) for Instances in cadence

    Quote Originally Posted by Dominik Przyborowski View Post
    Your PDK doesn't support multiplier parameter. You have to instantiate as vector as erikl said.
    Thank you Dominik,

    yes my PDK doesnt support the m factor,

    But indeed I didn't get how nstantiate as vector as erikl said in the CDFf symbol, it will be kind of you to explain me how

    Thank you once again



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  6. #6
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    Re: How to change the m factor (multiplication factor) for Instances in cadence

    Really? Sorry fellow but this question asking for RTFM.

    To instantiate any device in netlist unique name is needed. So to instantiate device, for example simple resistor as vector, you need to provide a proper name.
    R0<9:1> NET_A<9:1> NET_B<9:1> resistor 1k
    Above line instantiate 9 1kΩ resistors with one leg connected to 9 nets NET_A<9>,..., NET_A<1>, while other leg to NET_B<9>,..., NET_B<1> respectively.
    R0<9:1> NET_A NET_B resistor 1k
    While this line instantiates 9 1kΩ resistors in parallel connected between NET_A and NET_B.

    In Schematic editor, simply edit name of instance and add brackets with proper list order.

    In your virtuoso installation directory is a doc/ subdirectory containing a lot of helpful materials, with tutorials too.
    You can also access them from CIV→Help menu.


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