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Design >> Analog Design >> Programming Hspice ~
https://designers-guide.org/forum/YaBB.pl?num=1316660900

Message started by yuyulu on Sep 21^st, 2011, 8:08pm

Title: Programming Hspice ~
Post by yuyulu on Sep 21^st, 2011, 8:08pm

hello
does sb know how to implement a full adder?
i need a hspice code and circuit diagram
:)

Title: Re: Programming Hspice ~
Post by raja.cedt on Sep 22^nd, 2011, 7:22am

hello hspice is a circuit simulator..))

Title: Re: Programming Hspice ~
Post by Mohammad A Maktoomi on Sep 22^nd, 2011, 9:44am

Hi
Circuit diagram of CMOS full adder is available in books such as Rabaey and Weste/Harris.Or type "CMOS full adder" in google, you will get images.
I encourage you try writing spice code yourself. & believe me, its very easy. You can learn spice (by just giving few hours) from Rashid's book.

Title: Re: Programming Hspice ~
Post by loose-electron on Sep 26^th, 2011, 6:19pm

a transistor level simulation tool for a digital circuit function?

Well, yes it can be done, but sure you don't want a digital design tool and a functional level simulation?

Title: Re: Programming Hspice ~
Post by Mohammad A Maktoomi on Sep 26^th, 2011, 9:48pm

Dear Mr. loose-electron :)
pardon my little knowledge, but i think its not about "it can be done". after all, somebody has to design circuits at transistor level so that HDL people use them from library. Delay calculation, power dissipation, all these parameter is evaluated using lovely "SPICE". In case i sound wrong please guide me, as i am not much in HDLs(actually just started learning verilog).

Title: Re: Programming Hspice ~
Post by loose-electron on Oct 1^st, 2011, 2:50pm

Well, if you want to go that path then start by defining all the gates you need at the transistor level, and hook it all up. Set up the hirarchy at the higher levels and build from the bottom up.

As the device gets big, the simulations will get slow.

Title: Re: Programming Hspice ~
Post by Mohammad A Maktoomi on Oct 1^st, 2011, 8:15pm

Exactly sir. But,blocks like adders doesn't need gates to be defined in spice.one can translate the algo directly to transistor level(in CMOS). i will not be simulating a whole microprocessor using spice.Spice simulation (in digital design) is perhaps limited to library creation(digital IC design).one uses spice in designing data-path circuits, for example, as these blocks are critical in deciding the speed of system.