Lecture-08 - EEE 333: VHDL, L-08 Sequential Elements Fall...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 EEE 333: VHDL, L-08 EEE 333: VHDL, L-08 Fall 2008, ASU Yu (Kevin) Cao, yu.cao@asu.edu , GWC 336 Sequential Elements Sequential Elements EEE 333, ASU, Y. Cao Lecture 08 - 2 - Midterm 01 Midterm 01 ± Average: 35.4 ; top: 46 ± Standard deviation: 4.55 ± Letter grade: A+: top 10% A: > μ + 0.5· σ A-: > μ B+: > μ - 0.5· σ B: > μ – σ B-: > μ – 1.5 σ C: > μ - 2· σ D: else ± Welcome to see me if you have any questions 0 5 10 15 20 25 25 30 35 40 45 50 More Grade Student Number
Background image of page 1

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

View Full DocumentRight Arrow Icon
2 EEE 333, ASU, Y. Cao Lecture 08 - 3 - Highlight Highlight ± process statements ± if statements ± Latches and FFs ± Select signal statements ± Reading: Chapter 3, 5 in Ashenden’s book EEE 333, ASU, Y. Cao Lecture 08 - 4 - Process Statements Process Statements ± Syntax of Process process_label: process [(sensitivity_list)] is process_declarations begin sequential statement end process [process_label]; The process sensitivity list is an implicit “wait on sensitivity_list” at the end You can’t use both but must have one – otherwise the process will never be activated! ± Process can describe a logic block Outputs driven by a process can only be driven by that process An implicit key point: you need to think about how signals will be initialized or have their states changed on events
Background image of page 2
3 EEE 333, ASU, Y. Cao Lecture 08 - 5 - Process Execution Model Process Execution Model ± Executes once (at time = 0 ) runs until it hits a WAIT statement ± Time advances until the wait condition is satisfied Execution resumes only then ± Executes in an endless loop Interrupted only by wait statements The bottom of the process contains an implicit “go to the top” This makes it model hardware, which waits for inputs to change to do anything new ± Time does not advance within a process; it advances during a wait statement only EEE 333, ASU, Y. Cao Lecture 08 - 6 - Wait Statements Wait Statements ± Process advances during a
Background image of page 3

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

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 02/14/2011.

Page1 / 8

Lecture-08 - EEE 333: VHDL, L-08 Sequential Elements Fall...

This preview shows document pages 1 - 4. Sign up to view the full document.

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