1. 10/13/2009 1 Lab 6 - Algorithmic State Machines ECE238L 10/13/2009

2. 2 Multiple processes

3. 3 10/13/2009 Mealy Outputs State diagram Ref: Chapter 10, RTL Hardware Design Using VHDL

4. 4 10/13/2009 Mealy Outputs Revised state diagram (sm2) Y=1 / Y=0 / Y=1

5. 5 10/13/2009 ASM Chart An algorithm state machine (ASM), is an alternative method for representing an FSM. Although an ASM chart contains the same amount of information as a state diagram, it is more descriptive. It is usually used to specify complex sequence of events and actions needed to implement a control path. An ASM is composed of a network of ASM blocks.

6. 6 10/13/2009 ASM Block

7. 7 10/13/2009 ASM Block To reduce clutter, sometimes only the signals that are activated (asserted) are shown in the ASM. Example 1:

8. 8 10/13/2009 ASM Block Example 2:

9. 9 10/13/2009 ASM – More examples Example 3:

10. 10 10/13/2009 ASM – More examples A counter from 0 to 8; ASM representation: