microcontroller memory CRC

Started by Gary Peek in comp.arch.embedded14 years ago 1 reply

Does anyone know what typoe of CRC is being used with the Philips LPC9xx microcontrollers on the user code memory? It is 4 bytes but does not...

Does anyone know what typoe of CRC is being used with the Philips LPC9xx microcontrollers on the user code memory? It is 4 bytes but does not appear to be CRC-32. If the device is erased, or all zeros, the CRc returned is 00 00 00 00. (CRC-16 would return 00 00 as far as I can tell.) -- Gary Peek mailto:mylastname@mycompanyname.com Industrologic, Inc. http://www.indus...


ds18b20 invalid CRC problem

Started by Anonymous in comp.arch.embedded4 years ago 8 replies

Hello, I've have a temperature monitoring system using Maxim DS18B20 temperature sensors. To verify correct temperature, I compare the sensor...

Hello, I've have a temperature monitoring system using Maxim DS18B20 temperature sensors. To verify correct temperature, I compare the sensor crc (Byte8) in the sctatchpad with the calculated crc. Ninety nine percent of the time, the CRCs match and everything is fine, but occasionally, I get a CRC mismatch. After verifying against an online CRC checker I see that the sensor crc i


CRC calculation for variables stored in eeprom

Started by ssubbarayan in comp.arch.embedded10 years ago 7 replies

Dear all, I have posted a couple of months back about eeprom corruption and some experts here adviced me to stored a CRC value for the...

Dear all, I have posted a couple of months back about eeprom corruption and some experts here adviced me to stored a CRC value for the memory contents to determine corruption.Regarding this I have got a query: In our case,the contents in the eeprom change dynamically in run time.Does that mean everytime we need to update the CRC too?As an end user how would I know which value of CRC is ...


crc for versioning

Started by darkknight in comp.arch.embedded12 years ago 9 replies

Suppose you have some software that is 16K bytes. Is CRC16 - 16 bit crc, a reasonable way of producing a number that uniquely identifies a...

Suppose you have some software that is 16K bytes. Is CRC16 - 16 bit crc, a reasonable way of producing a number that uniquely identifies a particular revision of this software? What are the odds of two different revisions having the same CRC? Are they any better than using a 16 bit arithmetic checksum? TIA


ccitt crc error detection failure rate test program

Started by Shane williams in comp.arch.embedded6 years ago 15 replies
CRC

Out of curiosity, I've lashed up a program (see below) to try and test the detection failure rate for the ccitt 16 bit crc. It...

Out of curiosity, I've lashed up a program (see below) to try and test the detection failure rate for the ccitt 16 bit crc. It repeatedly generates a buffer of 32 pseudo-random bytes, calculates the crc, then complements 8 pseudo-random bits and re-calculates the crc. How many iterations should I have to run it for to get the same crc on the "corrupted" data as the non-corrupted data? T...


CRC calculation

Started by janka vietzen in comp.arch.embedded10 years ago 11 replies

for the moment I struggle with the modbus protocol checksum what seems to use a quite odd 16 bit CRC polynom 0xA001. I have no idea if my...

for the moment I struggle with the modbus protocol checksum what seems to use a quite odd 16 bit CRC polynom 0xA001. I have no idea if my ATmega assembly code works correct becouse its responsible for both directions generation and test same time and for the moment I do not have further modbus certificated devices. Is there any CRC calculator known what allows to comapare reference values? ...


0x07 or 0xE0 CRC

Started by karthikbalaguru in comp.arch.embedded8 years ago 7 replies
CRC

Hi, I find that the polynomial for CRC-8-ATM is 1 + x + x^2 + x^8 and the representations as 0x07 or 0xE0 in the below...

Hi, I find that the polynomial for CRC-8-ATM is 1 + x + x^2 + x^8 and the representations as 0x07 or 0xE0 in the below link http://en.wikipedia.org/wiki/Cyclic_redundancy_check Does it mean that 0x07 and 0xE0 based CRC calculation are inter-operable ? When/Where should we need to use 0x07 and When/Where should we need to use 0xE0 ? Why is it mentioned as either 0x07 or 0xE0 ? Any i...


Dallas DS18B20 CRC

Started by suppamax in comp.arch.embedded9 years ago 4 replies

Hi everybody. I've got a problem using Dallas DS18s20 temperature sensor. In particular, it seems to me it sends a wrong crc. Here's how I...

Hi everybody. I've got a problem using Dallas DS18s20 temperature sensor. In particular, it seems to me it sends a wrong crc. Here's how I use it. Firstly, I perform a temperature conversion, and a second later I read data stored in its scratchpad. Data regarding temperature and fixed values seems correct (temperature is correct, the other parameters are always the same), but the crc is...


sFPDP : Data frame with CRC and no data

Started by chinni in comp.arch.embedded8 years ago
CRC

hi all, I am involved in a project for validating the sFPDP core. My question is : In case the CRC feature is enabled for sFPDP frames, and...

hi all, I am involved in a project for validating the sFPDP core. My question is : In case the CRC feature is enabled for sFPDP frames, and if a data frame is to be transmitted with 0 bytes (Lets say to indicate the status of SUSPEND through GO/STOP field), what value do i need to put in the CRC field ? thanks in advance!!


CRC routine for 8051

Started by Ed in comp.arch.embedded8 years ago 3 replies

I need an encode/decode routine for CRC-CCITT Kermit for the x51 micro please. Thanks

I need an encode/decode routine for CRC-CCITT Kermit for the x51 micro please. Thanks


crc-8 dow table generation problem

Started by phesx in comp.arch.embedded11 years ago 4 replies
CRC

Hi to all, I have a problem with crc-8 dow algoritmic. x^8+x^5+x^4+1 CRC_DOW The problem is: I want implement the fast calculation but...

Hi to all, I have a problem with crc-8 dow algoritmic. x^8+x^5+x^4+1 CRC_DOW The problem is: I want implement the fast calculation but My CRC_table is different from the CRC_DOWN table reported in the web description: looking at the web I've founf the CRC table to calculate CRC_DOW (below an extract ... 0-15) CRC_DOWN right table (decimal format): 0, 94, 188, 226, 97, 63, 221, 131, 1...


Infiniband via Virtex-II Pro RocketIOs (keywords: Virtex2, RocketIO, Rocket I/O)

Started by Bruce in comp.arch.embedded13 years ago 1 reply

Hello, at present I am working on an Infiniband implementation on a Virtex-II Pro. As far as I know the build-in RocketIOs are fully compliant...

Hello, at present I am working on an Infiniband implementation on a Virtex-II Pro. As far as I know the build-in RocketIOs are fully compliant to the Infiniband standard (beacon and variant CRC excluded). There are two types of CRC, the invariant and the variant type. Although the RocketIOs are able to calculate at least one type, i.e. the invariant CRC, you cannot make use of it in this par...


CRC Kermit problem

Started by Ed in comp.arch.embedded8 years ago 2 replies

I found a C routine that calculates the CRC correctly OnCrctst() is a button to run it. I need a 8051 ASM routine to do the same thing or...

I found a C routine that calculates the CRC correctly OnCrctst() is a button to run it. I need a 8051 ASM routine to do the same thing or similar I can only find a few PIC routines which I cannot seen to follow. Please, someone help me..... Ed ============================================================================ #define P_KERMIT 0x8408 unsigned short up...


CRC of Preferred Roaming List problem

Started by Autumn-Fox in comp.arch.embedded12 years ago 3 replies

I have a problem with the crc calculation for the preferred roaming list. Here is a roaming list from a motorola phone Roaming List NAM 0: ...

I have a problem with the crc calculation for the preferred roaming list. Here is a roaming list from a motorola phone Roaming List NAM 0: 00 31 30 39 00 02 40 03 10 51 c8 49 8c 6b b9 6a b0 74 d8 e1 b8 6e 14 a3 70 89 94 a3 02 5d 63 47 84 57 41 15 e0 0c 08 22 bc 81 02 2b 9c 0a 06 98 dd The last two bytes are the 16 bit CRC...


compact flash/pcmcia without crc check

Started by Dave in comp.arch.embedded10 years ago 1 reply

Hello, One piece of equipment (Lecroy scope) takes a compact flash card via a PCMCIA adapter, but the combo must not implement a CRC check,...

Hello, One piece of equipment (Lecroy scope) takes a compact flash card via a PCMCIA adapter, but the combo must not implement a CRC check, or the scope can't write the card. I think this is implemented in the PCMCIA adapter rather than the card. Does anyone know of a PCMCIA/CF combination that doesn't do the CRC? Thanks, Dave


8-bit CRC

Started by Dan in comp.arch.embedded13 years ago 7 replies

I'm trying to implement the mux protocol (GSM 07.10) with a Motorola G18 modem. I have the spec ETSI TS 101 369 which describes the...

I'm trying to implement the mux protocol (GSM 07.10) with a Motorola G18 modem. I have the spec ETSI TS 101 369 which describes the CRC as: The FCS shall be the ones complement of the sum (modulo 2) of a) the remainder of xk (x7 + x6 + x5 + x4 + x3 + x2 + x1 + 1) divided (modulo 2) by the generator polynomial x8 + x2 + x + 1, etcetera... What I really want is the C code that implem...


TCP-IP CRC calculation in PCs

Started by Michael Schuster in comp.arch.embedded10 years ago 2 replies

Hi, just a silly Q we are discussing here. The CRC calculation for TCP-IP Protcols: Where is it calculated? In the CPU or the...

Hi, just a silly Q we are discussing here. The CRC calculation for TCP-IP Protcols: Where is it calculated? In the CPU or the network-card? Thanks Michael -- Remove the sport from my address to obtain email www.enertex.de - Innovative Systeml?sungen der Energie- und Elektrotechnik


Need an explanation for calculating the CRC for a CAN network

Started by Anonymous in comp.arch.embedded9 years ago 13 replies
CRC

Can anyone out there explain how to calculate the 15 bit CRC field for a Controller Area Network message (specifically the extended...

Can anyone out there explain how to calculate the 15 bit CRC field for a Controller Area Network message (specifically the extended frame format)? I don't understand the code given in the Bosch specification (not even sure which language it's written in) and the only other example I found was very obfuscated C code. Any takers? -Will


CRC calculation

Started by janka vietzen in comp.arch.embedded11 years ago

I dont have many modbus manuals but there are 2 diffrent code samples for crc written in C. One uses 2 bested byte - bit loops and the other uses...

I dont have many modbus manuals but there are 2 diffrent code samples for crc written in C. One uses 2 bested byte - bit loops and the other uses 255 byte lookup tables for low and highbyte each. Unfortunately I dont tried any Compilers for Atmels ATmega128 (probably there is a gcc available) and even the cpu family is new for me why i decided to start with assembler


Communication Check

Started by Fizzy in comp.arch.embedded11 years ago 1 reply
CRC

Hi, I am stuck with probably a very simple problem and need some immediate help. I require to establish some kind of data integrity scheme for...

Hi, I am stuck with probably a very simple problem and need some immediate help. I require to establish some kind of data integrity scheme for PLB communication. I ahve PPC405 acting as MASTER and two custom slave IPs. I don't know if CRC will work in this case??????? I am not very familiar with 64 bit PLB bus. Can i send the CRC every time i do the burst or line transmission???? All i am ...