Digital Teaching Aid (DED Philippinen, 86 p.)
 (introduction...)
 Preface
 Introduction
 Fundamental Logic Operations - Lesson 1
 Lesson Plan
 (introduction...)
 Introduction
 TTL circuits
 Logic operations
 Handout No. 1
 Worksheet No. 1
 Introduction Boolean Algebra - Lesson 2
 Lesson Plan
 Introduction
 Boolean algebra
 Boolean equations of logic circuits
 NOR and NAN gates
 De Morgan's theorems
 Worksheet No. 2
 Circuit Analysis and Design - Lesson 3
 Lesson Plan
 (introduction...)
 Introduction
 Boolean laws and theorems
 Sum of product method
 Design example
 Handout No. 2
 Worksheet No. 3
 First Evaluation
 Karnaugh Mapping - Lesson 4
 Lesson Plan
 (introduction...)
 Introduction
 Karnaugh map
 Truth table to Karnaugh map
 Pairs, Quads, and Octets
 Overlapping and Rolling
 Worksheet No. 4
 Karnaugh Mapping II - Lesson 5
 Lesson Plan
 (introduction...)
 Introduction
 Product of sums method
 Don't care conditions
 Worksheet No. 5
 Coding - Lesson 6
 Lesson Plan
 (introduction...)
 Introduction
 ASCII code
 Excess-3 code
 Gray code
 Encoder
 Decoder
 Code converter
 Worksheet No. 6
 Flip-Flops - Lesson 7
 Lesson Plan
 (introduction...)
 Introduction
 RS Flip-Flops
 D - Flip-Flop (D-FF)
 JK Flip-Flop (JK-FF)
 Worksheet No. 7
 Second Evaluation
 Counter - Lesson 8
 Lesson Plan
 (introduction...)
 Introduction
 Asynchronous counter
 Synchronous counter
 Seven segment indicator and decoder
 Worksheet No. 8
 Data Processing Circuits - Lesson 9
 Lesson Plan
 (introduction...)
 Introduction
 Multiplexer
 Demultiplexer
 Handout No. 3
 Worksheet No. 9
 Third Evaluation
 Answers to Evaluation Problems

### Worksheet No. 6

No. 1 Develop a decoder circuit for the conversion of the Gray code into the decimal system. Use a Karnaugh map to get a simplified circuit!

 Gray code decimal d c b a 0 0 0 0 0 0 0 0 1 1 0 0 1 1 2 0 0 1 0 3 0 1 1 0 4 0 1 1 1 5 0 1 0 1 6 0 1 0 0 7 1 1 0 0 8 1 1 0 1 9 X X X X . . . . . . . .

No. 2 Develop a code converter for the conversion of the excess 3 code into the 8421 code (BCD).

Complete the truth table!

Use Karnaugh maps to get a simplified circuit!

 Excess 3 code 8421 code dec d c b a d1 c1 b1 a1 0 0 0 1 1 0 0 0 0 1 0 1 0 0 0 0 0 1 2 0 1 0 1 0 0 1 0 3 0 1 1 0 0 0 1 1 4 0 1 1 1 0 1 0 0 5 1 0 0 0 0 1 0 1 6 1 0 0 1 0 1 1 0 7 1 0 1 0 0 1 1 1 8 1 0 1 1 1 0 0 0 9 1 1 0 0 1 0 0 1 1 1 0 1 1 0 1 0 1 1 1 0 1 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 1 1 0 1 0 0 0 1 1 1 1 0 0 0 1 0 1 1 1 1

The lower six rows are redundant.