LED Controller - Moore State Machine

Moore state machine with 4 states (init_t, seq1_t, seq2_t, seq3_t) animating a 4-LED bar.

Behaviour:

• Reset (i_reset='1'): state ← init_t, o_led ← "0001".
• While i_start='0', the state stays at init_t.
• On i_start='1', the FSM walks init_t → seq1_t → seq2_t → seq3_t → init_t on each rising edge.
• Each state lights a different LED: init_t→"0001", seq1_t→"0010", seq2_t→"0100", seq3_t→"1000".

*Moore output: o_led depends only on the current state. Asynchronous active-high reset.*