Digital concept an Number system Chapter 1 Digital system
Digital concept and Number system Chapter 1 Digital system
Diqital system entity can process, transfer and store any kind of diqital signals is Composed of individual digital logic circuits which are designed to erform specified function
Digital system: • entity • can process, transfer and store any kind of digital signals • is Composed of individual digital logic circuits which are designed to perform specified function
physical signal (transformation rule) Digital signal: discrete quantities Analog signal: continuous quantities PAM The difference between analog and digital lies in the method of Encoding information
•physical signal (transformation rule) • Digital signal: discrete quantities • Analog signal: continuous quantities The difference between analog and digital lies in the method of Encoding information
Digital logic circuit A circuit used to process digital signal All function of the circuit are realized by performing Boolean calculation or Boolean udament It operates on numbers that represent some real logical or arithmetic function
Digital logic circuit • A circuit used to process digital signal. • All function of the circuit are realized by performing Boolean calculation or Boolean judgment. – It operates on numbers that represent some real logical or arithmetic function
Digital logic circuit E= A+B E F4 F3 F2 F1 cO A4A3A2A1 B4B3B2B1 B
Digital logic circuit • E = A+B A4A3A2A1 B4B3B2B1 F4 F3 F2 F1 CO CI E A B “ 0
Digital logic circuit The basic logic functional units that perform primitive logic functions are called gates A 8 翻F(ABC)=AB+ABC+ABC 8 8
Digital logic circuit • The basic logic functional units that perform primitive logic functions are called gates. & A F B C & & + F(A,B,C)=AB+AB’C’+A’BC
Digital logic circuit The work signal is restricted to two binary values o. 1 o and 1 are logic value They can represent the voltage level of a circuit 1 is high level and o is low They also can represent the two states of transistors, conduct is defined as logic 1 and cutoff is logic O
Digital logic circuit • The work signal is restricted to two binary values 0, 1. – 0 and 1 are logic value. – They can represent the voltage level of a circuit , 1 is high level and 0 is low. – They also can represent the two states of transistors, conduct is defined as logic 1 and cutoff is logic 0
Digital logic circuit Studying the digital circuit we are concerned with the relationship between the input and output, the function it provide, not the internal detail Digital integrated circuits, constructed from electronic components, are designed to perform specified logic functions Simple integrated circuits contain a few logic gates is called small-scale integration(SSI contains 0 to 9 gates) Medium-scale integration(MSI contains 10 to 99 gates) Large-scale integration (LSI contains 100 or more gates Very large-scale integration (vLsi does not have a gate count but is usually thought of as more than 1000 gates)
Digital logic circuit • Studying the digital circuit , we are concerned with the relationship between the input and output, the function it provide, not the internal detail. • Digital integrated circuits, constructed from electronic components, are designed to perform specified logic functions. – Simple integrated circuits contain a few logic gates is called small-scale integration (SSI contains 0 to 9 gates) – Medium-scale integration (MSI contains 10 to 99 gates) – Large-scale integration (LSI contains 100 or more gates) – Very large–scale integration (VLSI does not have a gate count but is usually thought of as more than 1000 gates)
Digital logic circuit Level five Complex Systems, Function Units from levels Two through Four evel four More complex Function Logic Units, e.g. Third IC level(VLSI) microprocessor Level three Function Logic Units, e.g. adders Second ic level counters, multiplexers (MSI and LSI) Level two Function Logic Units, e.g. gates, NOT, AND, NAND, EX-OR First IC level (SSI) Level one Electronic Components, e.g. transistors, Components level diodes, resistors, capacitors
Digital logic circuit Components level First IC level (SSI) Level four Level three Level five Electronic Components, e.g. transistors, diodes, resistors, capacitors Function Logic Units, e.g. gates, NOT, AND, NAND, EX-OR Function Logic Units, e.g. adders, counters, multiplexers More complex Function Logic Units, e.g. microprocessor Complex Systems, Function Units from levels Two through Four Third IC level (VLSI) Second IC level (MSI and LSI) Level two Level one
Digital logic circuit Memory function Combinational logic circuits Sequential circuits Synchronous sequential circuits Asynchronous sequential circuits
• Memory function – Combinational logic circuits – Sequential circuits •Synchronous sequential circuits • Asynchronous sequential circuits Digital logic circuit
