数字电子技术(Floyd 第十版)课件Chapter 5.ppt

Summary Hardware Description Languages (HDLs) Another standard HDL is Verilog. In Verilog, the I/O and the logic is described in one unit called a module. Verilog uses specific symbols to stand for the Boolean logical operators. The following is the same program as in the previous slide, written for Verilog: module BCDInv (X, B, C, D); input B, C, D; output X; assign X = (B | C)D; endmodule Selected Key Terms Variable Complement Sum term Product term A symbol used to represent a logical quantity that can have a value of 1 or 0, usually designated by an italic letter. The inverse or opposite of a number. In Boolean algebra, the inverse function, expressed with a bar over the variable. The Boolean sum of two or more literals equivalent to an OR operation. The Boolean product of two or more literals equivalent to an AND operation. Selected Key Terms Sum-of-products (SOP) Product of sums (POS) Karnaugh map VHDL A form of Boolean expression that is basically the ORing of ANDed terms. A form of Boolean expression that is basically the ANDing of ORed terms. An arrangement of cells representing combinations of literals in a Boolean expression and used for systematic simplification of the expression. A standard hardware description language. IEEE Std. 1076-1993. 1. The associative law for addition is normally written as a. A + B = B + A b. (A + B) + C = A + (B + C) c. AB = BA d. A + AB = A ? 2008 Pearson Education 2. The Boolean equation AB + AC = A(B+ C) illustrates a. the distribution law b. the commutative law c. the associative law d. DeMorgan’s theorem ? 2008 Pearson Education 3. The Boolean expression A . 1 is equal to a. A b. B c. 0 d. 1 ? 2008 Pearson Education 4. The Boolean expression A + 1 is equal to a. A b. B c. 0 d. 1 ? 2008 Pearson Education 5. The Boolean equation AB + AC = A(B+ C) illustrates a. the distribution law b. the commutative law c. the associative law d. DeMorgan’s theorem ? 2008 Pearson