Review week 20: state machines

This week you built chips that remember what they are doing right now:

• State machine: a state number in a register. Every tick reads it and decides on the transitions. Work out transitions from the old state, take over the new one only at the end.
• Jump table: a chain of beq lines jumps into the block of the current state. The catch branch sends every unknown state into the fault state. No jumps to computed line numbers.
• Time in states: a counter in ticks (0.5 s), reset in the one place where the new state is taken over. Waiting times and timeouts become ordinary transitions.
• Fault and acknowledge: latch the first cause, clear it only with a button and only without a current reason, show the cause as a number.
• Big code: fixed sections, a register plan, subroutines with their own registers.

You pass from 60 %. The explanations after handing in sum up every point once more.