1. Write the logic function from input to output step by step according to the given logic diagram;

2. Simplify logic function by formula method or Karnaugh map;

3. List the truth table from the simplified output function expression;

Summarize the logical functions of combinational circuits from logical expressions or truth tables.

Design steps:

1 Carefully analyze the design requirements and determine the input and output variables.

2 Assign 0 and 1 to the input and output variables, and list the input-output correspondence table, that is, the truth table, according to the causal relationship between input and output.

Fill in the Karnaugh map according to the truth table and write the logical function expression in an appropriate form.

Draw a logic circuit diagram.