Design a 4-bit 4×1 multiplexer using four 4×1 multiplexers. The output should be a single 4-bit output. I’m attaching my current work. The wiring is wrong and I can’t figure out how to fix it. This is the feedback from instructor: Here is the problem, the designed 4*1 mux (4-bit) is not wired correctly. e.g, you need to assert the first bit of all the inputs to the first mux block (1-bit).
The Correct Answer and Explanation is :
To design a 4-bit 4×1 multiplexer (MUX) using four 1-bit 4×1 multiplexers, follow these steps:
- Understanding the Components:
- A 1-bit 4×1 MUX selects one of four 1-bit inputs based on two selection lines (S1 and S0) and outputs the chosen bit.
- A 4-bit 4×1 MUX selects one of four 4-bit inputs, outputting a 4-bit word.
- Constructing the 4-bit MUX:
- Use four 1-bit 4×1 MUXes, each handling one bit of the 4-bit data.
- Connect the selection lines (S1 and S0) to all four MUXes to ensure simultaneous selection across all bits.
- For each MUX, assign the corresponding bit from each 4-bit input to its data inputs.
- Wiring Details:
- Each 4-bit input (D0, D1, D2, D3) consists of four 1-bit inputs (D0[3:0], D1[3:0], etc.).
- Connect D0[0] to the data input of the first MUX, D0[1] to the second, and so on.
- This ensures that when a particular 4-bit input is selected, all its bits are correctly routed through the MUXes.
- Instructor’s Feedback Addressed:
- By connecting all selection lines to all MUXes and properly assigning data inputs, each MUX operates in unison, selecting the appropriate bit from the chosen 4-bit input.
Explanation:
A multiplexer is a digital switch that selects one of many inputs and forwards it to a single output line. In this design, we aim to construct a 4-bit 4×1 MUX by leveraging four 1-bit 4×1 MUXes. Each 1-bit MUX is responsible for selecting one bit from the four 4-bit inputs based on the selection lines.
By ensuring that all MUXes share the same selection lines and are correctly wired to handle the corresponding bits, we achieve a synchronized operation where the output reflects the selected 4-bit input across all bits.