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Message
From: waman mainkar <waman_m@y...>
Date: Tue, 7 May 2002 17:51:18 -0700 (PDT)
Subject: RE: [ethmac] got my CRC running(mine is not)
Hi,
Thnaks for the suggestions. I am posting my code here.
So if any of you guys can have a look at it and
suggest me something. I'll appriciate that.
Thanks,
Waman.
module rxfcs
(RxClk,Reset,CrcEn,RxDI,CrcOut,CrcBuffer);
input RxClk, Reset, CrcEn;
input [7:0]RxDI;
output CrcOut;
output [31:0] CrcBuffer;
wire [7:0] RxDI;
wire RxClk, Reset, CrcEn;
reg CrcOut;
reg [31:0] CrcBuffer;
// polynomial: (0 1 2 4 5 7 8 10 11 12 16 22 23 26
32)
// data width: 8
// convention: the first serial data bit is D[7]
function [31:0] CountCrc;
input [7:0] Data;
input [31:0] CRC;
reg [7:0] D;
reg [31:0] C;
reg [31:0] NewCRC;
begin
D = Data;
C = CRC;
NewCRC[0] = D[6] ^ D[0] ^ C[24] ^ C[30];
NewCRC[1] = D[7] ^ D[6] ^ D[1] ^ D[0] ^ C[24] ^
C[25] ^ C[30] ^
C[31];
NewCRC[2] = D[7] ^ D[6] ^ D[2] ^ D[1] ^ D[0] ^
C[24] ^ C[25] ^
C[26] ^ C[30] ^ C[31];
NewCRC[3] = D[7] ^ D[3] ^ D[2] ^ D[1] ^ C[25] ^
C[26] ^ C[27] ^
C[31];
NewCRC[4] = D[6] ^ D[4] ^ D[3] ^ D[2] ^ D[0] ^
C[24] ^ C[26] ^
C[27] ^ C[28] ^ C[30];
NewCRC[5] = D[7] ^ D[6] ^ D[5] ^ D[4] ^ D[3] ^
D[1] ^ D[0] ^ C[24] ^
C[25] ^ C[27] ^ C[28] ^ C[29] ^ C[30]
^ C[31];
NewCRC[6] = D[7] ^ D[6] ^ D[5] ^ D[4] ^ D[2] ^
D[1] ^ C[25] ^ C[26] ^
C[28] ^ C[29] ^ C[30] ^ C[31];
NewCRC[7] = D[7] ^ D[5] ^ D[3] ^ D[2] ^ D[0] ^
C[24] ^ C[26] ^
C[27] ^ C[29] ^ C[31];
NewCRC[8] = D[4] ^ D[3] ^ D[1] ^ D[0] ^ C[0] ^
C[24] ^ C[25] ^
C[27] ^ C[28];
NewCRC[9] = D[5] ^ D[4] ^ D[2] ^ D[1] ^ C[1] ^
C[25] ^ C[26] ^
C[28] ^ C[29];
NewCRC[10] = D[5] ^ D[3] ^ D[2] ^ D[0] ^ C[2] ^
C[24] ^ C[26] ^
C[27] ^ C[29];
NewCRC[11] = D[4] ^ D[3] ^ D[1] ^ D[0] ^ C[3] ^
C[24] ^ C[25] ^
C[27] ^ C[28];
NewCRC[12] = D[6] ^ D[5] ^ D[4] ^ D[2] ^ D[1] ^
D[0] ^ C[4] ^ C[24] ^
C[25] ^ C[26] ^ C[28] ^ C[29] ^
C[30];
NewCRC[13] = D[7] ^ D[6] ^ D[5] ^ D[3] ^ D[2] ^
D[1] ^ C[5] ^ C[25] ^
C[26] ^ C[27] ^ C[29] ^ C[30] ^
C[31];
NewCRC[14] = D[7] ^ D[6] ^ D[4] ^ D[3] ^ D[2] ^
C[6] ^ C[26] ^ C[27] ^
C[28] ^ C[30] ^ C[31];
NewCRC[15] = D[7] ^ D[5] ^ D[4] ^ D[3] ^ C[7] ^
C[27] ^ C[28] ^
C[29] ^ C[31];
NewCRC[16] = D[5] ^ D[4] ^ D[0] ^ C[8] ^ C[24] ^
C[28] ^ C[29];
NewCRC[17] = D[6] ^ D[5] ^ D[1] ^ C[9] ^ C[25] ^
C[29] ^ C[30];
NewCRC[18] = D[7] ^ D[6] ^ D[2] ^ C[10] ^ C[26] ^
C[30] ^ C[31];
NewCRC[19] = D[7] ^ D[3] ^ C[11] ^ C[27] ^ C[31];
NewCRC[20] = D[4] ^ C[12] ^ C[28];
NewCRC[21] = D[5] ^ C[13] ^ C[29];
NewCRC[22] = D[0] ^ C[14] ^ C[24];
NewCRC[23] = D[6] ^ D[1] ^ D[0] ^ C[15] ^ C[24] ^
C[25] ^ C[30];
NewCRC[24] = D[7] ^ D[2] ^ D[1] ^ C[16] ^ C[25] ^
C[26] ^ C[31];
NewCRC[25] = D[3] ^ D[2] ^ C[17] ^ C[26] ^ C[27];
NewCRC[26] = D[6] ^ D[4] ^ D[3] ^ D[0] ^ C[18] ^
C[24] ^ C[27] ^
C[28] ^ C[30];
NewCRC[27] = D[7] ^ D[5] ^ D[4] ^ D[1] ^ C[19] ^
C[25] ^ C[28] ^
C[29] ^ C[31];
NewCRC[28] = D[6] ^ D[5] ^ D[2] ^ C[20] ^ C[26] ^
C[29] ^ C[30];
NewCRC[29] = D[7] ^ D[6] ^ D[3] ^ C[21] ^ C[27] ^
C[30] ^ C[31];
NewCRC[30] = D[7] ^ D[4] ^ C[22] ^ C[28] ^ C[31];
NewCRC[31] = D[5] ^ C[23] ^ C[29];
CountCrc = NewCRC;
end
endfunction
always @(posedge RxClk or negedge Reset)
begin
if (CrcBuffer == 32'h c704dd7b) //magic number
begin
CrcOut <= 1'b1;
end
else
begin
CrcOut <= 1'b0;
end
end
//end
always @(posedge RxClk or negedge Reset)
begin
if(!Reset)
begin
CrcBuffer <= 32'h FFFFFFFF;
end
else
begin
if(CrcEn==1'b1)
begin
CrcBuffer <= CountCrc (RxDI,CrcBuffer);
end
else
begin
CrcBuffer <= 32'h FFFFFFFF;
end
end
end
endmodule
--- Illan Glasner <iglasner@z...> wrote:
> Hi,
>
> Most likely you either append the crc wrongly or
> the data bit are put wrongly in the formula.
>
> a short suggestion, look on the 4 bit file I Email
> and see how I append the data and the crc to the
> equation and how the equation compare to the one
> given in asics site.
>
> that see that your do similar of course with 8 bit
> and equation different BUT the order should be the
> same.
>
> I enclose an example for the 32 bit which I did the
> same as I did the 4 bit, again the first run is to
> generate the crc than I took the crc value put it as
> data and than in the second run where you need to
> use +define+second_run you will get the magic
> number. this should help you get on the right track.
>
> have a nice day
>
> Illan
>
>
> -----Original Message-----
> From: waman mainkar [mailto:waman_m@y...]
> Sent: Monday, May 06, 2002 5:52 PM
> To: ethmac@o...
> Subject: Re: [ethmac] got my CRC running(mine is
> not)
>
>
> HI,
> i have got the equation from www.easic.be for 8 bit
> data path and CRC-32....
> and then for this function i am providing input 8
> bit
> data and a updating value of buffer like:
>
> crcbuffer = countcrc [this is function]
> (RxDI[data],crcbuffer);
>
> and then on the positive edge of clk i am comparing
> it
> with the magic no. and if it is equal then CRCOK in
> 1....
>
> i believe this logic is correct. but, i am not able
> to
> test it. so can anybody help me. i'll really
> appriciate that.
>
> waiting for replies.
>
> Thanks,
>
> Waman.
>
>
>
>
> --- "Christian R. Brecht" <Brecht@c...> wrote:
> > Hi all!
> >
> > Thank you very much for your help! Finally I have
> a
> > running version of my
> > CRC (which in fact was never wrong, I just used it
> > the wrong way )-: )...
> >
> > You've bee a big help! Thx!
> >
> > Christian
> >
> >
> >
>
-------------------------------------------------------
> > Christian R. Brecht
> > Brecht@c...
> >
>
-------------------------------------------------------
> >
> > ----- Original Message -----
> > From: "Illan Glasner" <iglasner@z...>
> > To: <ethmac@o...>
> > Sent: Monday, May 06, 2002 7:47 PM
> > Subject: FW: [ethmac] CRC question
> >
> >
> >
> > Hi,
> >
> > From some reason my replay Email didn;t
> > appear till now so I will
> > re-send it in hope this time it will pass the
> > barrier.
> >
> > have a nice day
> >
> > Illan
> >
> > -----Original Message-----
> > From: Illan Glasner
> > Sent: Friday, May 03, 2002 9:59 AM
> > To: 'ethmac@o...'
> > Subject: RE: [ethmac] CRC question
> >
> >
> >
> > Hi,
> >
> > Hope the following files will help you and
> any
> > other who might be
> > struggling with this crc as well as anyone who use
> > crc RTL code in his
> > behavoral instead of using task.
> >
> > crc4.v :
> > basicly the first run you simple compile it and it
> > calculate crc for few
> > data.
> >
> > than I took this data which have the crc value and
> > push it back and got the
> > magic number.
> >
> > for the second run you need to use th
> > +define+second_run
> >
> > of course the second run 8 extra data are
> determine
> > from the first run so it
> > is not "general" solution but it should help yu
> see
> > why you don;t get the
> > right value in your crc
> >
> > crc_calc_task.v
> > to make your simulation more effective I also
> added
> > a task that you should
> > use in any behavioral test bench which will
> > calcualte the crc in zero time.
> >
> > if you are intrested in how the crc equation are
> > constract this task is the
> > starting point as it have the basic single bit
> > formula and than you can
> > expand it for using it for any width as well as
> > using De-Morgan rules you
> > can get the equation for any width. (or simple go
> to
> > asics site and get it
> > done more quickly).
> >
> > have a nice day
> >
> > Illan
> >
> >
> >
> > -----Original Message-----
> > From: Christian R. Brecht
> [mailto:Brecht@c...]
> > Sent: Friday, May 03, 2002 3:42 AM
> > To: ethmac@o...
> > Subject: [ethmac] CRC question
> >
> >
> >
> > Dear All!
> >
> > I know this is not an ethmac question but for you
> > this will be an easy one:
> > I am working on my diploma work right now and for
> > some reasons I cannot use
> > your ethernetcore as we need some special things
> > implemented. But one thing
> > is similar: the CRC in general.
> > I guess I understood the CRC itself but for me it
> > seems the CRC-32 for
> > ethernet needs some weird extras like inverting
> the
> > 32 bits and reflecting
> > them as well. I will have to initialize the
> register
> > with "F"s as the first
> > step.
> >
> > Q: After all, usually I have to put zeros into the
> > CRCC. Do I have to put 0s
> > into this CRC-32C as well, or do I need to put Fs
> to
> > get it run (I need
> > nibbles for input). The problem is I have two
> > "testpatterns", one does the
> > job (60 Bytes of zeros work with mine) the other
> > doesn't. I used the CRC-32
>
=== message truncated ===
> ATTACHMENT part 2 application/octet-stream
name=crc32.v
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