Signed Multiplier


Create a 4 bit Signed Multiplier with the following specifications:

A 4 bit 2’s complement binary number. This could be positive or negative.
B 4 bit 2’s complement binary number. This could be positive or negative.

OUTPUT: 8 bit 2’s complement binary number (This could be a positive or negative number)

The overall circuit should look like this:

At a minimum, the circuit must be implemented using controlled inverters and an unsigned multiplier as discussed in class:

1) The Controlled Inverters and Unsigned multiplier must be implemented as sub-circuits as demonstrated in class. These sub-circuits are used to build the 2’s Complement Signed Multiplier.
2) You are only allowed to use the basic gates: AND, OR, XOR, NOT.
3) You are NOT allowed to use Logisim’s built in circuits (i.e. Adders and Multiplexers). However, you are allowed to use the basic gates to build your own Adders and Multiplexers.
4) Once completed, please ZIP your CIRC file in the following format:
For example:
5) Upload your project via Blackboard.
6) Work on the project individually. This is not a group project.

bout the App

App name: Logisim
App description: logisim (App:
App website:
Install the App

Press Command+Space and type Terminal and press enter/return key.
Run in Terminal app:
ruby -e “$(curl -fsSL” /dev/null ; brew install caskroom/cask/brew-cask 2> /dev/null
and press enter/return key.
If the screen prompts you to enter a password, please enter your Mac’s user password to continue. When you type the password, it won’t be displayed on screen, but the system would accept it. So just type your password and press ENTER/RETURN key. Then wait for the command to finish.
brew cask install logisim
Done! You can now use Logisim.
Type of paper: program through logisim


Sample Solution