Quantcast PARALLEL ADDERS

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-8 When A, B, and the carry-in are all HIGH, a sum of 1 and a carry-out are produced. First, consider A and B. When both are HIGH, the output of gate 1 is LOW, and the output of gate 2 is HIGH, giving us a carry-out at gate 5. The carry-in produces a 1 output at gate 3, giving us a sum of 1. The output of the full adder is 112. The sum of 12 plus 12 plus 12 is 112. PARALLEL ADDERS The adders discussed in the previous section have been limited to adding single-digit binary numbers and carries. The largest sum that can be obtained using a full adder is 112. Parallel adders let us add multiple-digit numbers. If we place full adders in parallel, we can add two- or four-digit numbers or any other size desired. Figure 3-9 uses STANDARD SYMBOLS to show a parallel adder capable of adding two, two-digit binary numbers. In previous discussions we have depicted circuits with individual logic gates shown. Standard symbols (blocks) allow us to analyze circuits with inputs and outputs only. One standard symbol may actually contain many and various types of gates and circuits. The addend would be input on the A inputs (A2 = MSD, A1 = LSD), and the augend input on the B inputs (B2 = MSD, B1  = LSD). For this explanation we will assume there is no input to C0 (carry from a previous circuit). Figure 3-9. —Parallel binary adder. Now let’s add some two-digit numbers. To add 102 (addend) and 012 (augend), assume there are numbers at the appropriate inputs. The addend inputs will be 1 on A2 and 0 on A1. The augend inputs will be 0 on B2 and 1 on B1. Working from right to left, as we do in normal addition, let’s calculate the outputs of each full adder. With A1 at 0 and B1 at 1, the output of adder 1 will be a sum (S1) of 1 with no carry (C1). Since A2 is 1 and B2 is 0, we have a sum (S2) of 1 with no carry (C2) from adder 1. To determine the sum, read the outputs (C2, S 2, and S1) from left to right. In this case, C2 = 0, S2 = 1, and S1 = 1. The sum, then, of 102 and 012 is 0112  or 112. To add 112 and 012, assume one number is applied to A1 and A2, and the other to B1 and B2, as shown in figure 3-10. Adder 1 produces a sum (S1) of 0 and a carry (C1) of 1. Adder 2 gives us a sum (S2)


Electrical News
Top 10 Candidates for Next-Gen Storage
What's the next step in the evolution of memory? This...
eetimes.com
A Taste of LabVIEW
I attended an introduction to LabVIEW workshop to get some...
eetimes.com
Designing for Wearables: Tremendous Opportunity but Not Without Challenges
The wearables space is wide open and exploding with opportunity,...
edn.com
Memory Product Round Up: September 2014
Summaries of memory products making news this month, including SD...
eetimes.com
Some Days You're the Pigeon, Others You're the Statue
Are cities still commissioning new statues, or is this practice...
eetimes.com
M2M & IoT Meet Asset Tracking
The advent of highly integrated and low cost Field Programmable...
eetimes.com
Where's the Silicon in Silicon Valley?
An engineer who has experienced firsthand the changes that the...
eetimes.com
Teardown.com Analysis: Apple iPhone 6 Plus
Qualcomm appears but not as RF, and the A8 is...
eetimes.com
Maker Faire Meets the Big Apple
Hundreds of large companies, startups, maker spaces, and scientists converged...
eetimes.com
Why You Can't Judge a Company by Its Version 1.0 Product
You really don't need to spend your valuable time fighting...
eetimes.com
Inside Intel's Gen 8 GPU
Intel recently gave a tour inside the workings of its...
eetimes.com
Australian Crowd Source Equity Funding Report
I have been made aware of this Australian government requested...
eevblog.com
Startup's Piezoelectric MEMS Mics May Take Over
By using piezoelectric diaphragm, Vesper claims its MEMS mics today...
eetimes.com
EEVblog #664 – Peltier TEG Energy Harvesting Experiments
Dave plays around with an energy harvesting kit to see...
eevblog.com
Tesla Model S – Australian Test Drive
Dave test drives one of the first right hand drive...
eevblog.com
What Apple Stuffed Inside iPhone 6 Plus
The iPhone 6 Plus packs a host of new tech...
eetimes.com
Secure WiFi Shield for Arduino Platforms
The Arduino Wi-Fi Shield 101 is designed to enable rapid...
eetimes.com
Digital Level Shifting
Do you need to take your signals to the next...
eetimes.com
Steve Wozniak Reacts to Latest iPhone
Being presented with his very own iCups communications system certainly...
eetimes.com
Five Challenges to FPGA-Based Prototyping
The state-of-the-art has progressed spectacularly since early forays into FPGA-based...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +