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
50G Ethernet Debate Brewing
The Ethernet Alliance will host a discussion on the future...
3G/4G Rising for M2M
3G and 4G cellular networking is on a rapid rise...
Europe Leads in Chip Market Growth
In July, Europe showed the strongest year-on-year growth of all...
Trillion Sensors Not Likely
The trillion-sensor world is not going to happen anytime soon....
IoE: Internet of Earthquakes?
Data scientists at Jawbone recently published findings on the quake's...
Apple iPhone 6: Mobile Payments Pioneer?
Apple's latest iPhone could help bring mobile payments to the...
MIPS Moves Multicore Battle to Clustering
Imagination Technologies launches its I-class I6400 MIPS 64-bit processor with...
How to Fly Without Catching the Dreaded Lurgy?
On returning from his trip to Brazil, Max was diagnosed...
Anatomy of an ARM Server Chip
Four out of the top five server IC companies prefer...
IoT Gives Old Technology New Life
Cypress Semiconductor sees a great deal of potential for SONOS...
Andes Ready to Rumble in CPU War
With ARM reigning as king of the CPU IP market...
D-PHY, M-PHY & C-PHY? First Look at Testing MIPI's Latest PHY
One of the significant advantages of MIPI Alliance standards is...
Homeless in Silicon Valley
Over Labor Day, I thought about the situation for the...
Wireless Net Takes the Next Train
The first products are about to adopt the new 802.15.4p...
EEVblog #659 – Medical Plugpack Teardown
What’s inside an IEC60601-1 medical class 5V mains DC-DC plugpack?...
Ethernet Links Go Green
Everything that uses energy uses too much if it. Energy...
Android Wear: Where Are the Wares
Here are examples of some of the watches that use...
Intel Wearables Contest Goes New Age
Emotional prosthetics, modular smartbands and sixth sense necklaces make up...
EEVblog #658 – Mailbag
Mailbag Monday. Dave opens his mail Spoilers: Keithley 177 Multimeter...
EEVblog #657 – Maker Faire 2014 Interviews
Some interviews from the 2014 Sydney Mini Maker Faire at...

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 +