Download presentation

Presentation is loading. Please wait.

Published byKelli Crowhurst Modified over 3 years ago

1
Lab 03 :Vending Machine System : Slide #2 Slide #3 Logic Gate Equations: Slide #4 Vending Machine System: Older Generation IC Technology:

2
Each logic gate has a Boolean equation to represent its operation. Lab 03 : Logic Gate Equations : Slide #2 Input AOutput X Boolean Equation: NOT Input AOutput X Boolean Equation: Input A Output X Input B OR Boolean Equation: Input A Output X Input B AND

3
Step 3: Draw the Digital System Diagram : Group variables that are ANDed together into a single block. This block is called product term (P-Term). Lab 03 : Vending Machine System: Design a logic system for a vending machine that will dispense a 75 cent surprise gift package if any of the following conditions occur… Three quarters are inserted. A dollar is inserted. The machine can only accept quarters and a dollar coin / note. Step 1: Declare Inputs and Outputs: Inputs : Quarters (Q1, Q2, Q3). Dollar (L). Logic 1 = currency present. Outputs : Package (P). Quarter Change (C). Logic 1 = dispense item. Q3 Q2 Q1 L P C Step 2: Generate Equation for the system: Dispense Package if Quarter1 and Quarter2 and Quarter3 OR Dollar is inserted. Dispense change if dollar is inserted. P = Q1 Q2 Q3 + L C = L P-Term : thus : P = + L Work from output towards input. P must be connected to an OR gate. L = + L Re-insert the P-Term (Q1 Q2 Q3). A 3 input AND gate is required. Q1 Q2 Q3 Connect L to OR gate and connect C to L (C=L). Once the system diagram is complete it can be used to test the operation of the system. Here is what happens when someone inserts 3 quarters. 0 1 1 1 1 0 1 1 0 1 0 0 0 0 1 0 1 1 Here is what happens when someone inserts a dollar. Here is what happens when someone searches their pocket finds a quarter and inserts it into the machine. Then they realize that they do not have 2 more quarters! If they insert a dollar what would be the result? 0 1 0 0 0 0 0 0 0 The result: The package and the change would be dispensed. The un-happy user of the machine would have paid $1 ($1.25 - $0.25 change). To resolve this problem an extra change output could be added. 1 1 0 0 0 1 0 1 1 C2C2 1 1 1 Slide #3

4
Lab 03 : Older Generation IC Technology : Older generation IC technology such as TTL ICs (transistor, transistor, logic) could often require students to interconnect 5 to 15 ICs. The wiring would often be very complex and messy. Complex designs looked so messy that the term spaghetti factory was used to describe the appearance of the wiring. Slide #4

Similar presentations

OK

ECE 331 – Digital System Design Basic Logic Functions, Truth Tables, and Standard Logic Gates.

ECE 331 – Digital System Design Basic Logic Functions, Truth Tables, and Standard Logic Gates.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on active directory services Ppt on content addressable memory cisco Ppt on eid festival india Ppt on aerobics step Ppt on computer hardware components Download ppt on teamviewer Ppt on 3-phase squirrel cage induction motor Ppt on network theory of memory Ppt on power system stability examples Ppt on agriculture insurance in india