FLIP FLOP & COUNTERS OVERVIEW

PART 3: Asynchronous Counters

(20 pts)  About 3 days

Here we’ll put together more complex asynchronous counters.  First we’ll build a modulus counter that will allow us to set the starting and ending value of the counter.  Then we’ll build in the functionality to be able to suspend the counter and the ability to reset the counter.

 Download the part 3 rubric

The first thing we get to work on in this unit is our understanding of the Flip Flop.  Flip Flops are a tool that we can use in a digital circuit that helps us store single bits of information (individual 0’s/1’s) for use later on in the circuit.  Flip Flops come in two flavors: “D Flip Flops” and “J/K Flip Flops” that both can be used to hold bits of information.  We’ve seen them used in previous circuits that we built to make counters and random number generators.  Here we will investigate Flip Flops further and start to look at how they can be used in more complex circuit design.

GRADING & PROCESS

 Take notes on the function of both D-Flip Flops and J/K-Flip Flops

 Take notes on applying Flip Flops in the creation of the Transparent D Latch

 Complete the Flip Flop Assignment

Flip Flop Explained

What’s Due In Flip Flops & Counters Part 1: Flip Flops

Here’s what’s due in Part 1: Flip Flops

1.  Take notes on the two kinds of Flip Flops and how they function
2.  Take notes on some of the applications of Flip Flops
3.  Complete the Flip Flop Assignment
4.  Have Benshoof check-off your assignment

Flip Flops are relatively simple tools that can have very cool and complex applications.  Earlier you should have looked at event detection and how the Flip Flop can be used to trigger other actions in a circuit.  Here we get to look at how Flip Flops can be used as “shift registers”.  A shift register is a circuit that simply passes single bits of information ‘left’ or ‘right’ along the circuit.  Flip Flops are perfect for this.  In this part of the unit we’ll learn a bit about shift registers and see them in action as we build our first simple asynchronous counter.

GRADING & PROCESS

 Take notes on the Asynchronous Counter and its function

 Complete the Shift Registers Assignment

 Complete the Simple Counter Assignment

What’s Due In Flip Flops & Counters 2: Shift Registers

Here’s what’s due in Part 1: Wiring

1.  Notes on Asynchronous Counters
2. Shift Registers Assignment
3.  Asynchronous Counters Assignment
4.  Have Benshoof check-off your careful drawing

Asynchronous counters take advantage of the functionality of Flip Flops to keep track of values and help units ‘carry over’ as they add up.  We can even use the different components of a Flip Flop – like the reset and preset pins – to make our counters stop at maximum values, or reset their overall count.  Here in this part of the unit you’ll investigate different types of asynchronous counters as you build them and get them working in Multisim and with the PLD.

GRADING & PROCESS

 Complete the Asynchronous Counter: Mod Counter Assignment

 Complete the Asynchronous Counter: Suspend/Reset Counter Assignment

 Complete the Asynchronous Counter: Now Serving Counter Assignment

What’s Due In Flip Flops & Counters Part 3: Asynchronous Counters

Here’s what’s due in Part 3: Build It!

1.  Complete the Mod Counter Assignment
2.  Complete the Suspend/Reset Counter Assignment
3.  Complete the Now Serving Counter Assignment
4.  Have Benshoof check-off your finished, working Bug Bot

The purpose of this unit is to give you lots of exposure to the D- and J/K-Flip Flops.  You should be able to identify what the different pins in the flip flop do, and be able to identify situations where a flip flop can help make a circuit more effective.  You should have investigated different applications of flip flops as well such as event detection and shift registers.  A lot of the time was spent in this unit creating counter circuits as well and getting them working on PLDs.  All together, the expectation is that you understand the big ideas of how flip flop works and when they are useful tools.

Benshoof Checkpoints

 (Part 1) Benshoof should have seen your working wiring before you moved on

 (Part 2) Benshoof should have seen your careful drawing before you moved on

 (Part 3) Benshoof should have seen your working Bug Bot