Questions tagged [crc]
CRC, or Cyclic Redundancy Check, is a technique commonly used to detect accidental changes to data
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Maximum message size for polynomial CRC-8 0x07 and hamming distance = 3
I am looking for maximum message size for my CRC-8 0x07 polynomial for Hamming distance = 3. Do you know some website with these types of information? Or possibly, do you know how to calculate it? I ...
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2answers
197 views
CRC calculations by hand do not match online calculator
I have been trying to understand what is the trick behind online calculator which gives me CRC value for any input. The thing is that results I get with doing maths by hand do not match results this ...
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1answer
38 views
Microchip 48LM01 memory secure read operation CRC and STM32 hardware CRC
I'm trying to use STM32 hardware CRC calculation mechanism to get CRC value from this data (3 byte address and 128 bytes of data):
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1answer
195 views
CRC calculation
I have been attempting to understand the CRC calculation. I have found online CRC calulator and I have done an experiment.
I have tried to calculate with this calculator the CRC16-CCITT (in the ...
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1answer
248 views
How to create a nested for-loop in Verilog?
I try to create a CRC module on Verilog.
The CRC calculating use an LFSR and can be fully-sequential (with two cycles), semi-sequential (with one cycle) or parallel. I have already made sequential ...
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40 views
How to calculate resultant of 32 bit CRCs
Im working on automotive controller and I have following question
I have list(about 6) of 32 bit CRCs and I want to combine them to get a resultant one
can I 'OR' or 'XOR' them to get resultant one?
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40 views
Does libusb_bulk_transfer add CRC?
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I'm writing a user interface program for USB device in C++ using Visual Studio 2019. I'm using libusb library. I want to do bulk transfer to the device, and I'm trying to understand the exact ...
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2answers
184 views
CRC calculation different for IC
I try to read out data from the AS5047U sensor (https://ams.com/documents/20143/36005/AS5047U_DS000637_1-00.pdf/8639418f-6c3a-1624-4e6f-18f52c962099) over SPI, but somehow my CRC is always different ...
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69 views
CRC Algorithms Basics
I am reading about CRC algorithms. And have a few basic doubts
Referred Link
I have 3 questions :
Suppose, I have a Microcontroller and an EEPROM. I have read that CRC employs different algorithms....
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2answers
149 views
What is the method to determine the XOR placing in CRC code with random generator
I'm reading a lot of different tutorials about how to implement CRC gates for different generators, But I couldn't understand the method.
For example, for the following generator, this example states ...
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2answers
453 views
Append calculated CRC to data and recalculate does not yield zero
I have been working on understanding CRC calculations for implementation in VHDL. Specifically I have implemented the CRC-32C (polynomial = 0x1EDC6F41) a couple of ways. First using an LFSR approach ...
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65 views
CRC in CAN Messages
I would like to know the difference between CRC calculation in CAN physical layer vs CRC calculation in the application layer. How does the CRC calculation in these layers affect the ASIL (Automobile ...
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1answer
450 views
Calculate CRC-16/Maxim in VHDL
I try to do a CRC-16/Maxim calculation in VHDL.
My current implementation looks as follows
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1answer
138 views
Revising CRC value after data adjustment
I have a 181 bytes data stream with 4 bytes CRC32 value at the end. The entire message length is 185 bytes.
The data stream is stored in the FPGA onchip memory and waiting to put into wire by TCP.
...
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1answer
152 views
CRC generator polynomial for data flash memory storage
I have been facing a problem how to implement embedded software configuration parameters management system. It means how to implement a software module which will be responsible for storage of for ...
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0answers
101 views
Incorrect ethernet crc code
I am trying to use the ethernet phy on my FPGA. I am at the point where I can receive a frame. The frame I can see using chipscope matches the data of the frame sent from my computer which I can ...
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1answer
234 views
Calculating number of errors that is undetected by a CRC using a particular polynomial
My goal is to determine optimal generator polynomial and size of the Frame Check Sequence (CRC field) for protocol that I am developing. Reading the paper, "Cyclic Redundacy Code (CRC) Polynomial ...
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1k views
CRC hardware implementation
What is the difference between these two implementations as the feedback is in first implementation the last reg only but the second implementation last reg xored with the input bit, so, what is the ...
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1answer
937 views
Verilog parallel CRC with arbitrary polynomial
for my next project I need to implement a CRC IP core in Verilog HDL. It must use 16bit polynomial and 16bit CRC result register. Data is being fed into it in 8bit chuncks / bytes. I have allready ...
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2k views
How is crc5 calculated for a usb token?
I captured the usb packets on a usb1.1 mouse using a generic 24mhz logic analyzer.
here is the sigrok capture for the first token.
as per the usb docs.. a CRC5 is calculated for the token by taking ...
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1answer
337 views
How does the rollback work in a FIFO?
From reading the book titled "Advanced Chip Design practical examples by verilog", I faced some questions about when the Ethernet packet is read from the FIFO and how the rollback works for the ...
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1answer
488 views
C++ - Help Interpreting the instructions of a CRC error-checking programming assignment
This is unconventional, based on what I've seen, but I can't get a hold of my professor's aides to clarify this assignment. I hope this is still ok to post here.
I would greatly appreciate some help ...
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1answer
875 views
CRC implementation for ethernet
With an example for data with a hexadecimal value of 0xda and a polynomial 0x07, I would find the CRC as follows (using the ...
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2answers
3k views
How to use the data CRC of SD cards in SPI mode?
I am interfacing an SD card through SPI using an AVR microcontroller (more specifically it is the Uzebox console).
I can successfully initialize the card with turning CRC check ON with CMD59 (so I ...
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2answers
3k views
SENT CRC calculation
I am using SENT protocol in my project.
In my SENT implementation, the data nibbles are 3. So 12 bit data, including a status nibble and CRC nibble.
I need to calculate the CRC for 3 data nibbles.
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1answer
1k views
Help identifying checksum
I need help identifying the checksum algorithm in the following packets please.
So, packets format is:
sd ?? dd dd dd ??
where
s = start nibble
d = data (binary coded decimal)
? = unknown - ...
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4answers
214 views
Best value to overwrite old to tell if memory is not used on eeprom
I have an EEPROM I want to store CRC32 hashes on between 0x0000 and 0x008C. In this range I need a way that I can erase one of the hashes and overwrite its bytes to a default number. By doing this I ...
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3answers
1k views
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 ...
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2answers
752 views
How to get up to 24 I/O pins from the PIC4550
Im trying to implement and understand the CRC by making a circuit, by using 1 byte (8 bits), and a highest power of the polynomial of four, these 2 values should be XORed until i get a final output, ...
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2answers
4k views
FCS verification of ethernet frame
i am trying to transmit a Ethernet frame from fpga to pc.
my udp frame is:
...
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0answers
1k views
CRC32 on SAM D20 (Cortex M0+)
I've been having a hard time debugging the DSU module on a SAM D20 (datasheet). I mean to utilize it to calculate CRC32 for a program I'm uploading through a custom bootloader (bootloader not mine).
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1answer
166 views
Parallel-In-Serial-Out with Parity?
Can someone recommend a shift register IC with integrated parity or CRC generator? Is there such a thing anyway?
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482 views
Help reverse engineering a CRC-8 [closed]
I have an arduino based home temperature monitoring system using Ambient Weather F007th wireless Thermo-Hygrometers as sensors. I am trying to work out the CRC and add some code to my project to ...
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1answer
341 views
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 ...
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1answer
453 views
CRC polynomial and Parity Error detection
My question is about the CRC generator polynomial.
If I have a generator of level 5, say:
$$X^5+X^4+X^2+1$$
How can I know if it can or cannot detect a parity error?
Also how can I know the error ...
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2answers
400 views
Finding an input sequence given a generating polynomial and CRC
I am working on a circuit that inputs a 31-bit pseudo-random binary string into a CCITT CRC-16 block which generates a 16-bit CRC output.
I know that M(x)/G(x) = Q(x) + R(x) and the transmitted code ...
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3answers
1k views
Reverse-engineering IR check bits/CRC
I'm trying to build a simple Arduino-based IR remote control for a cheap toy IR-controlled helicopter (same as this one - it's called "Diamond Gyro" or "Diamond Force"). I've decoded the IR protocol ...
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2answers
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My CRC8 is dysfunctional and I'm not sure why!
So I'm interfacing an arduino with a Melexis temperature sensor, and it's going okay--aside from the fact that I can't seem to get the CRC check to work.
I've gotten read operations to complete ...
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2answers
5k views
Implementing parallel CRC in verilog
I am trying to implement a parallel CRC in Verilog but having trouble getting it to work. This is a snippet of the code that I'm having trouble with.
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1answer
849 views
What is the purpose of CRC_IDR in STM32 processors?
The STM32's CRC calculation unit has a register named CRC_IDR. This 32 bit register allows the user to store 8bits of data. There seems to be no link between this register and rest of the CRC ...
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2answers
5k views
CRC for eeprom data check
I wanted to check redundancy in eeprom and crosscheck the data for any errors occurred or not and I ended up reading CRC code. I found it useful but have some doubts that need clarity.
My objective ...
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2answers
3k views
EEPROM data check
I am communicating with an EEPROM chip with micro controller.
I am writing certain data in to specific addresses in EEPROM and needs to check the data occasionally. But I have no idea other than ...
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2answers
4k views
How can I implement Bluetooth Low Energy CRC in 24 bits?
According to the Bluetooth Core 4.0 specification, the Bluetooth Low Energy air packet has a 24-bit CRC with the following polynomial:
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3answers
1k views
Why is the data output of some ICs in two's complement form?
I've been looking into some ICs now. Some of them have the calculated result (data) in twos complement form, placed in register to be read by other IC. What is the logic behind converting the data to ...
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42k views
Calculating a simple CRC
In the datasheet for the ET1200 EtherCAT ASIC (page 94), I am told that I need to calculate a CRC of some of the 16-bit data in its EEPROM. The only description of this CRC is:
Low byte [of word 7] ...
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2answers
1k views
What's the correct form of this CRC algorithm
We are working on communication between AVR and a Crous PTZ.
We found its protocol and now we can turn it on and so.
We have problem with its CRC. This is Crous protocol doc (Got it here), at end of ...
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1answer
3k views
CRC-16 Calculation
I'm trying to calculate the CRC-16 in hex form using a seed of 0x0000. For your convenience, here's the polynomial for CRC-16
\$ x^{16} + x^{15} + x^2 + 1 \$
I have the following packet sequence ...
