Hardware interview practice
Classify timing-path startpoints and endpoints
A synchronous block contains primary inputs/outputs and edge-triggered registers. Which classification is correct for ordinary data paths?
Choose one
Answer choices
- A. A register D pin is always a startpoint and Q is always an endpoint because data flows from D to Q internally.
- B. Input-to-register, register-to-register, register-to-output, and input-to-output are the four basic classes; register Q and input ports can start paths, while register D and output ports can end them.
- C. Only register-to-register paths exist in STA; input and output delays are simulation concepts.
- D. Every path must start at a clock pin and end at another clock pin; data pins cannot be timing endpoints.