1. Combinational Functional Devices
Lecture No. 15
Combinational Functional Devices
Asalam O Aleikum students. I am Waseem Ikram.
This is the fifteenth lecture in a series of 45 lectures on Digital Logic Design.

2. Recap Half-Adder Full-Adder Parallel Binary Adder Carry Propagation
Look-Ahead Carry Generator
MSI 4-bit Adder
Cascading 4-bit Adders
5 minutes

3. BCD Adder BCD Addition and error conditions
Single digit BCD Adder Circuit (fig 1)
BCD error detection ckt. (tab 1,fig 2,3)
Connection of error detection ckt. (fig4)
8 minutes
Total 13 minutes

4. Cascading BCD Adders 2 digit BCD Adder (fig5)
Adding BCD numbers (tab 2, 3)
4 minutes
Total 17 minutes

5. Subtraction 2’s Complement Subtraction
2’s complement Subtraction example
Subtracter Circuit (fig 6)
4-bit Adder/Subtracter Unit (fig 7)
Cascading Subtracters (fig 8)
Addition/Subtraction examples (tab 4 5)
12 minute
Total 29 minutes

6. ALU MSI 4-bit ALUs Function of 74X381 ALU (tab 6) Cascading 16-bit ALU
74X functions
74X functions group carry
74X functions
Function of 74X381 ALU (tab 6)
Cascading 16-bit ALU
Group-Carry Look-Ahead (fig 9, 10)
8 minutes
Total 37 minutes