I am a programming student studying electrical engineering fundamentals on the side. I have come across two different methods for getting the result of an operation onto the bus.
- A decoder accepts the op code. Each operation has an enabler attached to the output. All operations are performed and the results are stored in the enablers. The enabler that is selected gives the output of the operation.
- The output of each operation provides the input for a multiplexer. The op code is the selection input for the multiplexer. The output of the multiplexer is then put onto the bus.
Is there anything functionally different between these two variants? What are the advantages and disadvantages?