第二章门电路 2.1概述 2.2分离元件门电路 2.3TTL与非门 2.4其它类型的TTL门电路 2.5MOS门电路

第一章数字电路基础 1.1数字电路的基础知识 1.2基本逻辑关系 1.3逻辑代数及运算规则 1.4逻辑函数的表示法 1.5逻辑函数的化简

Synchronous sequential circuit memory, usually consisting of flip-flops, update circuit states information All flip-flops share a common clock pulse input The clock input is not a binary value representing the time of day but rather a\synchronous\train of pulses. Synchronous memory changes its data only at certain time intervals The flip-flops can change state only on a clock pulse edge

Analysis Analyze existing circuits to determine their function Synchronous sequential circuit The basic modeling structure Two circuit models: Mealy model& Moore model Three approach used to describe the circuit: Logic function equation

Sequential Circuit Models Yo Combinational logic Universal combinational circuit model No memory units No feedback from logic outputs back to the inputs

Registers, formed from collection of flip -flops, are used to store or manipulate data or both. Input and output function associated with registers include Parallel input/ Parallel output Serial input/ Serial output Parallel input/ Serial output OSerial input parallel output

simple counters Counting is a fundamental function of digital circuits. A digital counter consists of a collection of flip-flops that change states (set or reset) in a prescribed sequence

FLIP-FLOPS Add the certain combinational logic circuit to the input of the original flip- flop New

FLIP-FLOPS Flip-flops are digital devices that have the ability to store binary information after the excitation input has changed. They are considered to be the basic memory cell for the majority of electronic binary data storage applications. This section explores the flip-flop from a functional perspective

Let be the set of all input variables, X={, X1, .Xn} Let y be the set of all output variables, y={Y, 1 ...m} o The combinational function, F, operated on the input variable set, to produce the output variable set y. o The output is related to the input as