218L13S09 - ESE218 Lecture 13: Latches Outline Memory in...

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

View Full Document Right Arrow Icon
3/17/09 ESE218 Spring 2009 Lecture 13 1 ESE218 Lecture 13: Latches Outline ± Memory in Digital systems ± Latches ± SR ± S/R/ ± Gated latches ± D-latch ± Circuits with latches ± Summary
Background image of page 1

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

View Full DocumentRight Arrow Icon
3/17/09 ESE218 Spring 2009 Lecture 13 2 Sequential circuit structure Outputs Memory cells Combinational circuit Inputs
Background image of page 2
3/17/09 ESE218 Spring 2009 Lecture 13 3 Unstable and Bi-stable elements V out time V out time 0 +5V +2.5V State 0 State 1 Metastable 1 2 3 4 5 6 1 2 3 4 Oscillators have ODD number of inverters in a chain with feedback Bistable element (memory cell) has to have EVEN number of inverters (1) (2) (3) V out V out (1) (2) (3) V in Actually there is a 3 rd state but it is metastable
Background image of page 3

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

View Full DocumentRight Arrow Icon
3/17/09 ESE218 Spring 2009 Lecture 13 4 SR-latch (NOR-based circuit) 2 3 1 5 6 4 RESET SET Q 5 6 4 8 9 10 Q Q’ R S R=0, S=0 Hold: no change R=0, S=1 Set: Q 1 Q’ 0 R=1 , S=0 Reset: Q 0 Q’ 1 Active-high inputs S and R .. with S=0, R=0 it is equivalent to a chain of two inverters with feedback SR latch has ACTIVE-HIGH INPUTS
Background image of page 4
3/17/09 ESE218 Spring 2009 Lecture 13 5
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 14

218L13S09 - ESE218 Lecture 13: Latches Outline Memory in...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online