{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

BME303_lecture7

# BME303_lecture7 - BME303 Intro to Computing Programmable...

This preview shows pages 1–13. Sign up to view the full content.

BME303 Intro. to Computing 1 Programmable Logic Array (PLA) A B C 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Connections AND Array Building blocks such as the full adder

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 2 Logical Completeness You now can implement ANY truth table with AND, OR, NOT gates! A B C D 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 0 1 0 0 0 1 0 1 1 1 1 0 0 1 1 1 0 1. AND: combinations that yield a "1" in the truth table. 2. OR: the results of the AND gates.
BME303 Intro. to Computing 3 2 Types of Logic Structures 1. Combinational Logic Circuit output depends only on the current inputs Stateless “Decision element” 2. Sequential Logic Circuit output depends on the sequence of inputs (past and present) stores information (state) from past inputs

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 4 Problem Language Machine (ISA) Architecture Algorithms Micro-architecture Circuits Devices Data Path Memory Storage Elements R-S Latch Gated D latch Register Logic Structures Decoder Mux (multiplexer) Adder Logic Gates NOT OR AND Other gates Transistors Devices, Circuits, … Bottom Up
BME303 Intro. to Computing 5 R-S Latch: Simple Storage Element R is used to “reset” or “clear” the element – set it to zero. S is used to “set” the element – set it to one. If both R and S are one, “out” could be either zero or one. – “quiescent” state -- holds ( STORE ) its previous value – note: if a is 1, b is 0, and vice versa 1 0 1 1 1 1 0 0 1 1 0 0 1 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 6 Clearing the R-S latch • Suppose we start with output = 1, then change R to zero. Output changes to zero. Then set R=1 to “store” value in quiescent state. 1 0 1 1 1 1 0 0 1 0 1 0 0 0 1 1
BME303 Intro. to Computing 7 Setting the R-S Latch • Suppose we start with output = 0, then change S to zero. Output changes to one. Then set S=1 to “store” value in quiescent state. 1 1 0 0 1 1 0 1 1 1 0 0

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 8 R-S Latch Summary R = S = 1 – hold current value of the output in latch S = 0, R=1 – set output value to 1 R = 0, S = 1 – reset output value to 0 R = S = 0 – both outputs equal one – final state depends on the electrical properties of gates
BME303 Intro. to Computing 9 R-S Latch (004_RS_Latch.lgi)

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 10 Gated D-Latch • Two inputs: D (data) and WE (write enable) – when WE = 1 , latch is set to value of D • S = NOT(D), R = D – when WE = 0 , latch holds (STORE) previous value • S = R = 1
BME303 Intro. to Computing 11 Gated D Latch (005_D_Latch.lgi)

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
BME303 Intro. to Computing 12 Register • An n-bit register
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 39

BME303_lecture7 - BME303 Intro to Computing Programmable...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online