C Program For Crc 12517

I have used your code & that of a few other sources and came up with differing results which i'm trying to work through. My first question is where/what one does about changing the code depending on whether the processor is big endian or small endian? The second question is if one reflects the data when creating the table rather than reflecting the message byte what values does one actual reflect.the index? The final table value?

Answer to C Programming: I'm writing a program for a CRC 12. As of right now I only need help on my calculation portion. A C-language program is included which produces CRC values which conform. A CRC calculation will find that beginning with a 16-bit CRC, such as CRC16-CCITT.

The index after it has been left shifted (WIDTH - 8)? Tu Hi Re Bombay Ringtone Free Download. • or to post comments.

Sounds like they just need to arrange their packing and then calculate a CRC on the packed data. No need for anything fancy, by the looks of it. Which makes me wonder why a simple Google isn't sufficient. Pack your data into your single packet. Then CRC that data.

Then change the packet's CRC to the value calculated. Then send the packet. Receive a packet.

Calculate a CRC of the packed data in that packet. Check it matches the CRC value stored in the packet. Unpack the data. At what point do you need to know ANYTHING about the structure of the data to calculate the CRC? And you only need to know about the structure of the data AT ALL when you first pack that data into the packet, without which you won't be ABLE to pack that data into the packet in the first place. Quite what's so difficult about this, I don't know.

If you've packed the data into a stored array in the packet, just calculate the checksum of that area of memory that holds the stored array (and nothing more). They are two, separate, distinct steps that have nothing to do with each other. Also, the barest minimum CRC / hashing example will provide you with EVERY bit of code you need in terms of the CRC / hash here. And every CRC / hash library I've ever seen is at most two functions - initialise hash, add data to hash. The return value of the latter is almost always the CRC/hash of the data so far. Hep Yek Tavla Indir on this page.

Sounds like they just need to arrange their packing and then calculate a CRC on the packed data. No need for anything fancy, by the looks of it. Which makes me wonder why a simple Google isn't sufficient. Pack your data into your single packet. Then CRC that data. Then change the packet's CRC to the value calculated.

Then send the packet. Receive a packet.

Calculate a CRC of the packed data in that packet. Check it matches the CRC value stored in the packet. Unpack the data. At what point do you need to know ANYTHING about the structure of the data to calculate the CRC? And you only need to know about the structure of the data AT ALL when you first pack that data into the packet, without which you won't be ABLE to pack that data into the packet in the first place. Quite what's so difficult about this, I don't know.

If you've packed the data into a stored array in the packet, just calculate the checksum of that area of memory that holds the stored array (and nothing more). They are two, separate, distinct steps that have nothing to do with each other. Also, the barest minimum CRC / hashing example will provide you with EVERY bit of code you need in terms of the CRC / hash here.

And every CRC / hash library I've ever seen is at most two functions - initialise hash, add data to hash. The return value of the latter is almost always the CRC/hash of the data so far.

Thanks for the suggestion ledow. Yeah Google will gives tons of theory! I am very new to this CRC stuff! So, i am unable to get the full context of this algorithm application. Do you have any source code snippet for CRC calculation of a single packet? And How to change the packet's CRC to the value calculated?

Please, share me sir! Yeah Google will gives tons of theory! I am very new to this CRC stuff! So, i am unable to get the full context of this algorithm application. Do you have any source code snippet for CRC calculation of a single packet? And How to change the packet's CRC to the value calculated?I suggest you listen to your teacher on whatever course it is you're doing, or do some simple research.

Calculating a CRC is something that there's several thousand pieces of example code out there for, whichever one you happen to need (and if you are able to just choose 'any' algorithm, choose one of the standardised CRC ones - the Wikipedia article on CRC will show you some). But, honestly, I can't believe that you want to write this code 'urgently' and can't get your head around the results of a simple Google search, bother to look on something like Wikipedia (which will come up in the top ten Google searches for it, I should think) or know how to put the CRC into the packet (you do know what a CRC is, right?

And how it would be represented in memory? And the whole POINT of the structures that you've been given with their members explicitly reserved for CRC storage?).

We help those who help themselves here. Just what, precisely, have you done so far apart from re-stating the task you were given? All I see is a homework question.

We don't answer those, we only steer. We've steered you plenty now. What have you actually got out of it? What progress have you made? How much data-packing, CRC-calculating code have you actually got written now? Seriously, this is first-year programming stuff and you can't even find your own source on Google?

You wouldn't have lasted two seconds programming in the pre-Google days where you had to read up on this stuff in books, or arrive at a solution of your own, and then write the code yourself. And, to answer part of your reply, programming is 50% theory, 10% writing, 40% debugging. If you can't read the 'theory' out there on these things and at least knock up a bit of consistently-working (if not 100% accurate) code, then I suggest you find yourself another task, course, hobby or career.