Binary multiplication

[JohnSym]

Hi 

I have an 8-bit binary number and i need to multiply it by an unchanging 4-bit binary number. I tried using adders, switches, and LEDs but quickly ran out of components in the Student Edition. Can anyone suggest another method? ie, a chip (or 2...) that i could import?

I'm not looking for someone to do my work for me, i'm just looking for some options. Binary multiplication seems to be a deep topic, and i'm pressed for time 😞

Thanks in advance

[Miguel_V · Accepted solution]

Hello,

Good multipliers are made the same way you would do it (for ALUs) just using arrays of gates. So in Multisim you can find multiple IC's under the TTL family or more (if you just use the search function) , that will allow you to connect more than 4 or gates at thesame time, etc. You can use these to bypass the limited number of components you might have (So instead of one or gate being one component, you get o chip that handles 4 of them a the same time). Just use the search function in the component selector, you'll find various ones you can use. Hope this helps.

Also incase you don't know how to make one, a quick google search should find you quite a few designs. I found this one that seems pretty straight forward to follow for example.

http://forum.allaboutcircuits.com/showthread.php?t=44324

Kind Regards,

[JohnSym]

Thanks for that. I got it figured out as you say, by breaking the multiplication down into its constituents and using half and full adders to resolve each digit. I went into it thinking it would simply be a matter of importing a single magical chip that would do the work for me 🙂 

Thanks again