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
Whisper Shouts Flexibility Sacrificed in Pursuit of Volume
Imagination is moving away from software defined radio and back...
eetimes.com
EEVblog #647 – Agilent 53131A Frequency Counter Oven Upgrade
Dave upgrades his HP/Agilent 53131A frequency counter with an ovenised...
eevblog.com
EUV Results Bogus, Says Analyst
A veteran industry watcher and an IBM expert are at...
eetimes.com
PCIe Disk Drive Needs New Tests?
On the edge of deployment, it's time to create a...
eetimes.com
Has Sharp Dug Itself Out?
Helped by demand for small and midsized LCD panels, Sharp...
eetimes.com
The Coming Revolution in Desktop Pick-and-Place Machines
In the case of today's super-small components, hobbyists desperately need...
eetimes.com
Emulation: Have It Your Way
'Have it your way' sounds like just the right strategy...
eetimes.com
Keysight Technologies Opens Its Doors
The former Electronic Measurement Group of Agilent Technologies has officially...
eetimes.com
Engineers Solve Analog/Digital Problem, Invent Creative Expletives
An analog engineer and a digital engineer join forces, use...
eetimes.com
Friday Quiz: EMC & ESD
Get your EMC/ESD head in gear for the 2014 EMC...
eetimes.com
Is Tesla's Gigafactory a Gigablunder for Panasonic?
Panasonic signed a deal with Tesla on a large-scale battery...
eetimes.com
Android, China Rise in Smartphones
Nearly 300 million smartphones shipped worldwide during the second quarter...
eetimes.com
Movidius Vision Processing Unit Enters 2nd Generation
Movidius announces a new chip and lays claim to the...
eetimes.com
Q'comm Shares a Wearable Strategy
The future of ubiquitous wearables will require more innovation than...
eetimes.com
3D Printing in Space
Among the technological advances that will make our dreams of...
eetimes.com
Sony, Panasonic, Japan Display Plan OLED Joint Venture
Sony Corp., Panasonic Corp., and Japan Display Inc. are working...
eetimes.com
Sony, TSMC Win Award for Silicon-Plastic Process Development
Sony and TSMC's paper describing a process to integrate a...
eetimes.com
What's the Best Traveling Toolkit?
When one is travelling, it can be really handy to...
eetimes.com
Power Week: Google's $1M Power Inverter Challenge - How Small Is Possible?
This week, Google, along with the IEEE, is offering a...
eetimes.com
Teardown: Oculus Rift Dev Kit 2 by iFixit
Using a Samsung Galaxy Note 3 display, Oculus Rift DK2...
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 +