Final answer:
To create a 5-to-32 decoder with 3-to-8 decoder modules, four 3-to-8 decoders are used along with two 2-to-4 decoders to handle the enable signals. The two 2-to-4 decoders determine which 3-to-8 decoder should be active, allowing one of the 32 possible outputs to be activated. A2, A1, and A0 inputs are the same for all decoders while A4 and A3 determine the active decoder.
Step-by-step explanation:
Designing a 5-to-32 Decoder Using 3-to-8 Decoder Modules
To design a 5-to-32 decoder using 3-to-8 decoders, you can use four 3-to-8 decoder modules to represent the 32 outputs. A 5-to-32 decoder requires 5 input lines that can encode 32 different outputs. We will be using the additional two inputs as enable inputs for the 3-to-8 decoders. One of the key points is to handle the enable signals correctly.
Consider the inputs to be A4, A3, A2, A1, and A0, where A4 and A3 are used to activate the correct 3-to-8 decoder, and A2, A1, and A0 are used as the inputs to these decoders. To determine which module to enable, we can use two 2-to-4 decoders (or implement the logic with gates) that take A4 and A3 as inputs.
Each 2-to-4 decoder will activate one of the four 3-to-8 decoders. The active low enable (E) of each 3-to-8 decoder will be connected to the output of the first 2-to-4 decoder and the active high enable (E) will be connected to the output of the second 2-to-4 decoder. This way, only one 3-to-8 decoder is enabled at any given time based on the combination of A4 and A3.
Here's the structure:
- A4 and A3 inputs to the first 2-to-4 active-low decoder.
- A4 and A3 inputs to the second 2-to-4 active-high decoder.
- Connect the outputs of the first 2-to-4 decoder to the E inputs of the four 3-to-8 decoders.
- Connect the outputs of the second 2-to-4 decoder to the E inputs of the four 3-to-8 decoders.
- A2, A1, and A0 are used as inputs for each of the 3-to-8 decoders, which will ultimately provide the 32 outputs when enabled.
This design ensures that for any 5-bit input binary number, only one of the 32 outputs is activated, as per the function of a 5-to-32 decoder.