14-SequentialAnalysis

14-SequentialAnalysis - Sequential Circuit Analysis Last...

This preview shows pages 1–5. Sign up to view the full content.

Sequential circuit analysis 1 Sequential Circuit Analysis Last time we started talking about latches and flip-flops, which are basic one-bit memory units. Today we’ll talk about sequential circuit analysis and design. First, we’ll see how to analyze and describe sequential circuits. State tables show the inputs, outputs, and flip-flop state changes for sequential circuits. State diagrams are an alternative but equivalent way of showing the same information. Combinational circuit Inputs Memory Outputs

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

View Full Document
Sequential circuit analysis 2 An example sequential circuit Here is a sequential circuit with two JK flip-flops. There is one input, X, and one output, Z. The values of the flip-flops (Q 1 Q 0 ) form the state , or the memory, of the circuit. The flip-flop outputs also go back into the primitive gates on the left. This fits the general sequential circuit diagram at the bottom. Combinational circuit Inputs Memory Outputs X Z Q0 Q1
Sequential circuit analysis 3 How do you analyze a sequential circuit? For a combinational circuit we could find a truth table, which shows how the outputs are related to the inputs. A state table is the sequential analog of a truth table. It shows inputs and current states on the left, and outputs next states on the right. For a sequential circuit, the outputs are dependent upon not only the inputs, but also the current state of the flip-flops. In addition to finding outputs, we also need to find the state of the flip-flops on the next clock cycle.

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

View Full Document
Sequential circuit analysis 4 Analyzing our example circuit A basic state table for our example circuit is shown below. Remember that there is one input X, one
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/27/2011 for the course CS 231 taught by Professor - during the Fall '08 term at University of Illinois at Urbana–Champaign.

Page1 / 17

14-SequentialAnalysis - Sequential Circuit Analysis Last...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online