Firing rule for Grafcet ConcurrentBranching Structure in Grafcet

Firing rule for Grafcet

Concurrent/Branching Structure in Grafcet

Hierarchical Structure Sub-GRAFCET

State Transition

Concurrent States Transition

Branching States Transition

Discrete-Event Modeling Example 1

Discrete-Event Modeling Example 2

Example: 3 -bit Gray Code Generator

GRAFCET of 3 -bit Gray Code Generator

Exercise ： Traffic Light Controller

FSM of Traffic Light Controller

GRAFCET of Traffic Light Controller

Exercise ： Signal Generator We want to design a circuit that, from a clock signal clk, gives origin to the signal output shown as: To model the discrete-event system of the signal generator using GRAFCET

Hardware Synthesis Using VHDL

VHDL synthesis of Grafcet Fundamental Block

VHDL synthesis of Grafcet Convergence AND

VHDL synthesis of Grafcet Divergence AND

VHDL synthesis of Grafcet Convergence OR

VHDL synthesis of Grafcet Divergence OR

Complete Synthesis of Grafcet Model

Synthesis of Grafcet Controller

VHDL code of Grafcet Controller

VHDL synthesis of Grafcet Controller

VHDL synthesis of Grafcet Controller library ieee; use IEEE. STD_LOGIC_1164. all; entity g 0 is port( clk : in std_logic; rst : in std_logic; OK : in std_logic; L 1, L 2 : in std_logic; V 1, V 2 : out std_logic; Start_M : out std_logic; Stop_M : out std_logic ); end g 0; architecture miat of g 0 is signal s 0, s 1, s 2, s 3, s 4 : std_logic; begin process(clk, rst) begin if rst='0' then s 0<='1'; s 1<='0'; s 2<='0'; s 3<='0'; s 4<='0'; elsif clk'event and clk='1' then if s 0='1' and OK='1' then s 0<='0'; s 1<='1'; elsif s 1='1' and L 1='1' then s 1<=‘ 0’; s 2<=‘ 1’; s 3<=‘ 1’; elsif s 2='1' and s 3='1' and L 2='1' then s 2<=‘ 0’; s 3<=‘ 0’; s 4<=‘ 1’; elsif s 4='1' then s 4<=‘ 0’; s 0<=‘ 1’; end if; end process; V 1<=s 1; Start_M<=s 2; V 2<=s 3; Stop_M<=s 4; END miat;

Synthesized Circuit Block Diagram

Simulated Timing Diagram