Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [parity]

28 questions
13
votes
5 answers

Why bother with even parity?

I am using an SPI peripheral in my application. The peripheral returns packets containing 15 data bits, plus an Even Parity bit for error detection. Therefore all zeros, and all ones both pass the parity check. This means that my microcontroller…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
7
votes
9 answers

For UART, should I use parity on a board level?

I am considering whether to use parity or not with my UART. It is a board level high speed (upwards of 115,200 baud) signal. The traces are very short (less than 2 cm), MCU to DSP, but they could pick up noise. During a logic analysing session using…
Thomas O
  • 31,546
  • 57
  • 182
  • 320
4
votes
1 answer

Single Bit Error Correction & Double Bit Error Detection

Can someone explain, in their own words, what Double Bit Error Detection is and how to derive it? An example of corrupted data and how to detect the double bit would be appreciated. I can do Single Bit Error Correction using parity bits as well as…
Mike John
  • 157
  • 1
  • 2
  • 7
4
votes
0 answers

Forward Error Correction code, Reed Solomon, Turbo Code, Low-density parity-check

I am new to FEC (Forward Error Correction). Pointers highly appreciated. I am experimenting software with configurable "error protections". Result improving as setting raise to 40%. Still not enough 'margin'. The software uses Reed Solomon inside.…
EEd
  • 989
  • 4
  • 12
3
votes
1 answer

Reverse-engineering RS-485 communication

I've been trying to reverse engineer the communications protocol used by my home domotics, which I was able to determine uses a RS-485 implementation. I'm using a USB RS-485 serial dongle and an oscilloscope and it's not been easy so far (I've…
xfze
  • 143
  • 8
2
votes
2 answers

std_logic_vector to unsigned conversion throwing incompatible error

Below is a VHDL code of a even/odd parity generator for a bus of given width. library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all; use ieee.math_real.all; entity paritygen is generic( WIDTH : positive := 8 ); …
nurabha
  • 887
  • 4
  • 14
  • 29
2
votes
0 answers

How does BICM work?

Can someone explain bit-interleaved coded modulation (BICM) in plain language, focusing on the practical mechanisms and properties rather than the deep analytical details? I found a few papers and articles on the subject, but they were all pitched…
Polynomial
  • 10,562
  • 5
  • 47
  • 88
2
votes
1 answer

Generate Event Parity with Logic Block

I was under the impression in order to generate 'Even Parity' you had to have an even number of bits... so how could that logic block only have one output? I am sure I am wrong but I am not sure what to do..
Joe Caraccio
  • 123
  • 4
2
votes
3 answers

Understanding IR Protocol Checksum generation

To control my AC with an Arduino, I'm trying to emulate the IR Remote. Not with another IR LED, but directly connected to the IR Receivers Signal wire on the board. Using the Arduino as a Logic Analyzer I was able to understand the Protocol to about…
Hypfer
  • 21
  • 3
2
votes
1 answer

GPS parity decoding, how to get D29 and D30 of previous bits?

According to ICD GPS 200C, to decode the bits of a word you need to have the bits 29 and 30 of the previous word, this means that to get the bits 29 and 30 of the previous word you should know the bits 29 and 30 of the word before and so on. Now my…
Salman Azmat
  • 402
  • 1
  • 6
  • 14
2
votes
1 answer

CRC/Parity/Hamming Protect 16-bit parallel bus

I've got a Cortex-M4 based MCU linked to a FPGA via a 16-bit parallel memory bus interface. In essence the FPGA behaves like an external memory mapped to the memory space of the MCU: the MCU presents an address followed by either a data word (write)…
Arne
  • 1,805
  • 3
  • 27
  • 43
1
vote
3 answers

Number of errors that can be detected with a single-bit even parity code word system?

How many errors can a transmission system which uses code words with 7 data bits and a single parity bit (Checking for Even parity) detect at the receiving end. While I am aware of the fact that any odd number of errors can be detected with this…
shehan.k
  • 13
  • 3
1
vote
1 answer

Why does the UART not report an error for a data byte with wrong parity?

I am trying to learn about UART Serial communication of the MSP430FR6989 from Texas Instruments. Datasheet User's Guide I doing a program where my UART will send a character through the TX pin of my microcontroller and receives it through the RX…
Embedded_Dude
  • 589
  • 4
  • 25
1
vote
3 answers

Unsure how arduino is interpreting RS232 signal

Disclaimer: I am a novice. I have an RS232 connection with an RFID tag reader which I am monitoring via software on a desktop computer as well as an Arduino. The device is configured with 8E1 parity. The arduino is (to the best of my knowledge) set…
Kevin de Haan
  • 23
  • 5
1
vote
2 answers

Effectiveness of Parity Checking

A parity bit lets a receiver know whether or not the an input is correct, given the number of 1's matches the logic behind the parity bit (be it even = 1, or odd =1). This seems very ineffective to me, and even 'corrupting' (not sure what the right…
Mahmud Ahmad
  • 259
  • 2
  • 8
1
2