218L6S09

# 218L6S09 - ESE218 Spring 2009 Lecture 6 1 ESE218 Lecture 6...

This preview shows pages 1–6. Sign up to view the full content.

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

View Full Document

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

View Full Document

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2/12/09 ESE218 Spring 2009 Lecture 6 1 ESE218 Lecture 6. Two-level implementations. Standard forms. Outline ¡ Implementations of algebraic expressions ¢ AND-OR vs NAND-NAND ¢ OR-AND vs NOR-NOR ¢ Open-drain, three-state and wired logic ¢ AOI and OAI ¡ Standard forms ¢ SOP and POS, form conversion ¡ Canonical standard forms ¢ minterms, sum of minterms ¢ Maxterms, products of maxterms ¢ form conversion ¡ Summary 2/12/09 ESE218 Spring 2009 Lecture 6 2 Implementations of algebraic expressions •Straightforward implementations •AND-OR for SOP form •OR-AND for POS form • Better implementations •NAND-NAND as equivalent to AND-OR •NOR-NOR as equivalent to OR-AND • THE BEST implementations •AND-OR-INVERT •OR-AND-INVERT •Circuits with open drain, wired logic Propagation delay Large Small 2/12/09 ESE218 Spring 2009 Lecture 6 3 NAND + inverter = AND AND gate is a two-stage circuit, it contains NAND gate and an inverter. The latter results in longer propagation delay compared to that in a single NAND gate a R +V DD b c=(ab)’ NAND R AND R +V DD a b ab (ab)’ NAND + Inverter 2/12/09 ESE218 Spring 2009 Lecture 6 4 AND-OR implementation SOP: F(A,B,C,D) = AB + CD A Too many inverters ⇒ longer propagation delay B C D 5 7408 1 2 3 7408 1 2 3 F AND =NAND+INVERTER OR = NOR+INVERTER Let us exclude the unnecessary inverters using properties of Boolean algebra! 2/12/09 ESE218 Spring 2009 Lecture 6 5 NAND-NAND implementation...
View Full Document

## This note was uploaded on 04/12/2009 for the course ESE 218 taught by Professor Donetsky during the Spring '08 term at SUNY Stony Brook.

### Page1 / 16

218L6S09 - ESE218 Spring 2009 Lecture 6 1 ESE218 Lecture 6...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online