Digital Electronics
Chapter 3 Gate-Level Minimization
Karnaugh Maps Simplify F =A'B'C + A'BC' + AB'C+A'BC + ABC
K-Map Simplify F =A'B'C + A'BC' + AB'C+A'BC + ABC F = C + A'B
K-Map with “don’t care” Simplify F(w,x,y,z) = Σ (1,3,7,11,15) d(w,x,y,z) = Σ (0,2,5) F = z (y + w' )
DeMorgan’s Picture! Two Equivalent Representations
How Bubbles Move ! F = AB + CD Three equivalent representations of F = AB + CD
NAND Implementation F = xy' + x'y + z
Designing for Equivalence Design a circuit to check if x = y
Hint: Review XOR and XNOR XNOR will be high if x = y
Odd and Even Functions (a) Checks for odd number of 1’s (b) Checks for even number of 1’s
Parity Generator / Checker Even Parity Generator Even Parity Checker P = 1 if x,y,z have odd number of 1’s so that the four bits, x, y, z, and P have an even number of 1’s C= 1 if there is error, that is if the four bits received have an odd number of 1’s
VHDL Verilog Hardware Description Language // A simple example module my_example (A,B,C,x,y); input A,B,C; output x,y; wire e; and g1 (e,A,B); not g2 (y,C); or g3 (x,e,y); endmodule
Comments on my_example // indicates a comment line statements are terminated with ; endmodule has no semicolon keywords like module, input etc. must be in lowercase gate declarations must have the output first then the inputs separated by commas
Circuit Diagram of my_example
That’s All Folks!