Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Explain about Hamming error correcting code?
Richard Hamming at Bell Laboratories worked out this code. We will only introduce this code with help of an illustration for 4 bit data. Let's presume a 4 bit number b4, b3, b2, b1. In order to create a simple error detection code which detects error in one bit only we can just add an odd parity bit. Though if we want to find which bit is in error then we may have to employ parity bits for different combinations of these 4 bits in such a way that a bit error can be recognized uniquely. For illustration we can create four parity sets as below
Source Parity Destination Parity
b1, b2, b3 P1 D1
b2, b3, b4 P2 D2
b3, b4, b1 P3 D3
b1, b2, b3, b4 P4 D4
Now very interesting phenomenon can be noticed in above displayed parity pairs. Assume data bit b1 is in error on transmission then it will cause alteration in destination parity D1, D3, D4.
ERROR IN Cause change in Destination Parity
(One bit only)
b1 D1, D3, D4
b2 D1, D2, D4
b3 D1, D2, D3, D4
b4 D2, D3, D4
Figure: The error detection parity code mismatch
So by simply comparing parity bits of source and destination we can recognize that which of four bits is in error. This bit then can be complemented to eliminate error. Please note that even source parity bit can be in error on transmission but under assumption that just one bit (irrespective of data or parity) is in error it would be detected as just one destination parity would be different. What should be length of error detection code that detects error in one bit? Before responding this question we have to look in comparison logic of error detection. Error detection is done by comparing two ‘i’ bit error detection and correction codes fed to comparison logic bit by bit (see figure below). Let’s have comparison logic that produces a zero if compared bits are same or else it generates a one. Consequently if similar Position bits are similar then we obtained zero at that bit Position however if they are dissimilar that is this bit position may point to an error then this Particular bit position would be marked as one. This way a matching word is built. This matching word is ‘i’ bit long so can signify 2i values or combinations.
SMTP Simple Mail Transfer Protocol, a protocol for sending e-mail messages among servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from si
how can we bimpliment half substractor using nand gate
diifference between pure and impure interpeter
Draw a circuit of an NMOS inverter and explain its operation
calculate the number of states per unit volume in an energy interval of 0.01eV above the Fermi energy of Na metal. The Fermi energy of Na at 0 K=3eV.
What is Priority interrupt. It is a system that establishes a priority over the several resources to determined which condition are to be serviced first when two or more reques
Direct Addressing and Immediate Addressing mode - computer architecture: Immediate Addressing: It is the simplest form of addressing. Here, the operand is itself given
The implementation of a (non-recursive) binary search of an array. The assumption is that a given array is sorted. We want to see if a particular value, that we'll call the target
The syntax of the assembler directive EQU is ? Ans. The syntax of the assembler directive EQU is as given below: EQU
Illustrate the Purchase Consummation activity? Purchase Consummation: This model lists three activities in the purchase consummation phase: • Receipt of product. • Pl
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd