Re: [bluetooth] Re: Re: Re: CRC sample dataquestion??pls reply ASAP

[ccsin@k7mail.com]

Hi Anil Nainwal and all members,

I think that my code is correct.Let me explain here,

In my Verilog code, I declared:
   uap[7:0]
   crc[15:0]
   data[7:0]]

I assume the Sample data (please check pg979) for "data" and "uap" are defined in 
this manner:

********LSB on the right,MSB on the left******

Therefore I load uap and data_in in the way shown below:

uap[7:0] = b'01000111 //0x47


data[0]=4e=01001110 ; data_in is 1st '0',2nd '1',3rd '1', 4th '1',5th '0',and so on //0x4e
   .
   .
   .
   .
   .
   .
data[9] = 09 = 00001001;data_in is 1st '1',2nd '0,3rd '0', 4th '1',5th '0'.......and so on


after all the data is fed, i got crc[15:0] = b64b 
but in the spec(on page 73), it stated that the bit15 should be out, then bit14...and so 
on.

therefore crc = d26d

what i suspect that they swap the 1st and 2nd byte,so crc = 6dd2


Am I right?? Anyone has done the CRC?? please tell me if i'm wrong. If you would like 
to check for me,i will send you the code

BTW,if i load uap = 57,and the data still remains the same,i got crc=a7ad, is it 
correct??

Thank You

Best Regards

Chuan Chew
-------------------------------------------------------------

----- Original Message ----- 
From: "Anil Nainwal - Sofblueindia" 
<anilnainwal@s... > 
To: "ChuanChew Sin" <ccsin@k... > 
<bluetooth@o... >, "Jamil Khatib"  
<khatib@o... > 
Date: Wed, 30 Apr 2003 10:29:36 +0530 
Subject: [bluetooth] Re: Re: Re: CRC sample dataquestion??pls reply 
ASAP 

> Dear Chuan, 
> 
> I went through your code. 
> 
> The problem that I could see is: 
> 
> In your module crc_ccitt , You have defined output [`BITS_OUT-1:0] 
> crc_out; 
> 
> This means that MSB is bit 15(16th bit) and LSB is bit 0. 
> Fine�. 
> 
> 
> 
> Now, UAP is 47 that is (0100 0111) with LSB on the left most side 
> i.e UP0(LSB) is 0 and UP7(MSB) is 1.--------(1) 
> 
>  Now, in both test benches, you have defined reg [`BYTE-1:0] uap, 
> this means if written in a format of (ABCD EFGH) , A will be MSB 
> and H is LSB 
> 
> CASE 1: Now, when you initialize uap in test bench crc_sim you are 
> initializing it as 
> 
> uap= `BYTE'h47; ie 0100 0111 
> 
>  it means msb (UP7) is 0 and LSB (UP0) is 1. now compare it with 
> (1) and you will find it's mismatching. So here is the problem. 
> 
> 
> 
> CASE 2: When you initialize UAP in crc_sim1, what you are doing 
> is� 
> 
>  uap= `BYTE'h2e; ie 0010 1110. 
> 
>  This means MSB (UP7) is 0,� UP5= 1� UP1=1 and 
> LSB(UP0)=0. 
> 
>  Now compare it again with (1) and you will find all the bits are 
> mismatching. 
> 
> 
> 
> I think Similar kind of problem is there while initializing others. 
> 
> Solution: 
> 
>  If you have defined reg [`BYTE-1:0] uap, then initialize uap as 
> (1110 0010) that comes to be E2. and not 2E. 
> 
>  But check the same problem while initializing other parameters as 
> well. 
> 
> 
> 
> Then one more solution that comes to my mind is you define reg 
> [0:`BYTE-1] uap, and then initialize it as in CASE 1, ie 47 (0100 
> 0111) this will make 0 as MSB and 1 as LSB. And this is same as 
> (1), I havenot tried it yet but you try and then please tell me if 
> it works. 
> 
> But do take care while initializing others, this is one basic 
> problem i could see on first go, I will check it more. but till 
> then you try this and also check that other initializations are 
> fine. 
> 
> you are welcome to put your queries.... 
> 
> If I am wrong..plz let me know.. suggestions will be appreciated. 
> 
> Best Regards 
> 
> Anil Nainwal 
> 
> 
> ----- Original Message ----- 
> From: "ChuanChew Sin" <ccsin@k... > 
> To: <anilnainwal@s... > 
> Sent: Tuesday, April 29, 2003 7:31 AM 
> Subject: Re: Re: Re: CRC sample dataquestion??pls reply ASAP 
> > Hi Anil Nainwal, 
> > 
> > Sorry to bother you again. 
> > 
> > Have you checked the code I sent to you yesterday??I really 
> hope that you could find out the problem that i'm facing right now. 
> > 
> > Best regards. 
> > 
> > Chuan Chew 
> 
> 
--
To unsubscribe from bluetooth mailing list please visit http://www.opencores.org/mailinglists.shtml