7485 for EWB 5.1 or MultiSim 2001

[RyGuye45]

Hi, I am trying to build and simulate a circuit with a 7485 magnitude comparator IC.  I have both EWB 5.1 and MultiSim 2001, but that IC wasn't available on my versions.  EWB technical support told me to come here and ask where to find the "SPICE model" for this component.  Also, even if I do find this model, I'd have no idea how to integrate it into my EWB or Multisim.  If anyone could help me with this that would be great.  Thanks!

[lacy]

Here's the 2001 Version Model:

.MODEL 7485 d_chip ( behaviour= "
+;7485   4 BIT MAGNITUDE COMPARITOR
+/inputs  A0 B0 A1 B1 A2 B2 A3 B3 A>B A<B A=B
+/outputs O_A>B O_A<B O_A=B
+/wires W00 W01 W02 W10 W11 W12 W20 W21 W22 W30 W31 W32 W41 W42
+;
+/module EOR_85
+/inputs A B
+/outputs O
+/table 4
+; A  B  O
+  L  L  H
+  L  H  L
+  H  L  L
+  H  H  H
+/endmodule
+/instance EOR_85 A0 B0 W00
+/instance EOR_85 A1 B1 W10
+/instance EOR_85 A2 B2 W20
+/instance EOR_85 A3 B3 W30
+;
+/module L10_85
+/inputs A B C D E
+/outputs O1 O2
+/table 3
+;  A  B  C  D  E  O1 O2
+   H  L  H  H  H  H  L
+   L  H  H  H  H  L  H
+   X  X  X  X  X  L  L
+/endmodule
+/instance L10_85 A0 B0 W10 W20 W30 W01 W02
+;
+/module L11_85
+/inputs A B C D
+/outputs O1 O2
+/table 3
+;  A  B  C  D  O1 O2
+   H  L  H  H  H  L
+   L  H  H  H  L  H
+   X  X  X  X  L  L
+/endmodule
+/instance L11_85 A1 B1 W20 W30 W11 W12
+;
+/module L12_85
+/inputs A B C
+/outputs O1 O2
+/table 3
+;  A  B  C  O1 O2
+   H  L  H  H  L
+   L  H  H  L  H
+   X  X  X  L  L
+/endmodule
+/instance L12_85 A2 B2 W30 W21 W22
+;
+/module L13_85
+/inputs A B
+/outputs O1 O2
+/table 3
+;  A  B  O1 O2
+   H  L  H  L
+   L  H  L  H
+   X  X  L  L
+/endmodule
+/instance L13_85 A3 B3 W31 W32
+;
+/module EXPAND_85
+/inputs A B C D E
+/outputs O1
+/table 2
+;  A   B  C  D  E  O1
+   H  H  H  H  H  H
+   X  X  X   X  X   L
+/endmodule
+/instance EXPAND_85 A>B W00 W10 W20 W30  W41
+/instance EXPAND_85 A<B W00 W10 W20 W30  W42
+/instance EXPAND_85 A=B W00 W10 W20 W30  O_A=B
+;
+/module OUTPUT_85
+/inputs A B C D E
+/outputs O1
+/table 2
+;  A  B  C  D  E  O1
+   L  L  L  L  L  L
+   X  X  X  X  X  H
+/endmodule
+/instance OUTPUT_85 W01 W11 W21 W31 W41 O_A>B
+/instance OUTPUT_85 W02 W12 W22 W32 W42 O_A<B
+;
+/delay 29
+;input output rise time fall time
+   A0   O_A<B   26n      30n
+   B0   O_A<B   26n      30n
+   A1   O_A<B   26n      30n
+   B1   O_A<B   26n      30n
+   A2   O_A<B   26n      30n
+   B2   O_A<B   26n      30n
+   A3   O_A<B   26n      30n
+   B3   O_A<B   26n      30n
+   A0   O_A>B   26n      30n
+   B0   O_A>B   26n      30n
+   A1   O_A>B   26n      30n
+   B1   O_A>B   26n      30n
+   A2   O_A>B   26n      30n
+   B2   O_A>B   26n      30n
+   A3   O_A>B   26n      30n
+   B3   O_A>B   26n      30n
+   A0   O_A=B   35n      30n
+   B0   O_A=B   35n      30n
+   A1   O_A=B   35n      30n
+   B1   O_A=B   35n      30n
+   A2   O_A=B   35n      30n
+   B2   O_A=B   35n      30n
+   A3   O_A=B   35n      30n
+   B3   O_A=B   35n      30n
+   A<B  O_A>B   11n      17n
+   A=B  O_A>B   11n      17n
+   A=B  O_A=B   20n      17n
+   A<B  O_A<B   11n      17n
+   A=B  O_A<B   11n      17n
+")

You'll have to create a symbol and I think you can use the pinout from the datasheet. Just plug this model in  try it. 

[RyGuye45]

Hey! thanks a bunch lacy for the model code, it should be really helpfull once I become more proficient with multisim, but for now it seems I'm a bit over my head.  With the PRE-loaded ICs like counters, 555s, adders, registers, and basic transistors etc.., I have no problem, but creating new components using SPICE is proving more difficult than I thought.  I'm just a first year EE student who got EWB 5.1 for free from my school, and my version of MultiSim 2001 out of my Intro to Digital Circuits textbook.  I know how the 7485 works and have a pin diagram with logic symbol with the datasheet, but I just couldn't figure out how to dovetale that into the 'add-component' function.  I think I'll just have to do some research on how all this SPICE stuff works, or buy the edu. or pro. edition with the 7485 already preloaded (unless that would be excessivly expensive).  If anyone knows of a good tutorial (at least more in depth than the one that NI provides) that could lead me step by step through the create-component function, that would be great.

p.s.  I'm working on a project that requires me to build an adjustably timed four way LED traffic light simulator using fixed function logic, and in all my preplanning, the 7485 comparator seems like an unavoidable compontent for the syncronization and timming I have to achieve.

[lacy]

If you keep looking around on the NI website I believe there may be a users manual for Multisim there somewhere (I think I remember seeing it but I can't be 100% sure of that fact. This may have been a while ago and it may not be there now.). The users manual probably would have a more detailed procedure in it for creating components.