This project hopes to integrate typical guitar audio effects unto a single IC. Using analog
amplifiers, filters, multiplexers, and digital control. The project also made use of a topology
voltage controlled variable resistor made completely of mosfets.
10. Control Signal Truth Table
Control1 Control2 M1 M2[1] M2[0] S1
0 0 X 0 0 0
0 1 0 0 1 1
1 0 1 1 1 1
1 1 1 0 1 1
The figure shown above shows how the select lines for the 2to1 and 4to1 multiplexers are
generated from the control signals inputted into the integrated circuit. The source follower
shown at the top of the image above is necessary due to low drive logic gates provide. A source
follower will be implemented for each output signal in order to drive the switching of the
multiplexers. The OR gate that generates the S1 output will be used to control if the
transmission gate is closed or not.
Control Logic for Multiplexer Select Lines
Verilog Code for Control Logic Generation
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