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AlastairM
Joined: 28 Apr 2008
Posts: 28
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| dsPIC30 printf 32-bit ints |
 Posted: Wed Jul 04, 2012 4:16 pm |
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Hi,
I'm using a dsPIC30F4011, MPLAB 8.85, CCS 4.134
I am having some strange printf results. Could someone explain if it's me or a bug?
| Code: | int16 buf[3];
int32 PackedData;
#use rs232(UART2,baud=19200,parity=N,bits=8,stream=DEBUG,errors)
buf[0]=0x169; //ADCBUF0;
buf[1]=0x2AA; //ADCBUF1;
buf[2]=0x355; //ADCBUF2;
PackedData=(((int32)buf[2])<<22)|(((int32)buf[1])<<12)|(((int32)buf[0])<<2);
fprintf(DEBUG,"%4LX,%4LX,%4LX = %8LX\r\n\r\n", buf[2],buf[1],buf[0],PackedData); |
output from MPLAB SIM
| Code: | Update Address Symbol Name Value Hex Binary
80E PackedData 0xD56AA5A4 0xD56AA5A4 11010101 01101010 10100101 10100100
808 buf
808 [0] 0x0169 0x0169 00000001 01101001
80A [1] 0x02AA 0x02AA 00000010 10101010
80C [2] 0x0355 0x0355 00000011 01010101 |
I'm Happy with that!
but output from serial
| Code: | 0355,02AA,0169 = FFFFFFFFD56AA5A4
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what are all those extra 'F's?
If I change it to
| Code: | buf[0]=0x69;
buf[1]=0xAA;
buf[2]=0x55; |
then I get on the serial:
| Code: | 0055,00AA,0069 = 154AA1A4
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(as an aside the print field width for hex numbers seems to be ignored)
Thanks
Al |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Jul 05, 2012 2:53 pm |
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I don't have that compiler but just to make an educated guess, I think
that because PCD has a "long long int" data type (64 bits) that it may be
sign-extending the value. Try casting the variable in the fprintf statement
to an int32. See if that fixes the problem.
In other words, CCS doesn't have separate printf format strings for all
the various sizes beyond a byte. In PCM and PCH, it has "%LX" which
is used to display both 16-bit and 32-bit values. There is no "%LLX".
So in PCD, they add an even larger type, 64-bits, to the same format
string. That's why I think casting the variable (inside the fprintf
statement) may fix the problem. At least it's something to try. |
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AlastairM
Joined: 28 Apr 2008
Posts: 28
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| Posted: Thu Jul 05, 2012 5:03 pm |
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| Quote: | | Try casting the variable |
That didn't work - I've admitted defeat, I assume there's a bug that thinks a 32-bit unsigned int with the MSB set is a 64-bit signed int.
Here's my gruesome workaround!
| Code: | | fprintf(DEBUG,"%4LX,%4LX,%4LX ... %4LX%4LX\r\n\r\n", buf[2],buf[1],buf[0],(int16)(PackedData>>16), (int16)PackedData); |
which gives the correct output on the serial:
| Code: | 0355,02AA,0169 ... D56AA5A4
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Thanks for your help
Al |
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AlastairM
Joined: 28 Apr 2008
Posts: 28
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| Posted: Tue Jul 10, 2012 2:30 pm |
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I've had an email from CCS Support:
| Quote: | | The problem you reported has been fixed and will be in the next compiler release. |
That was quick! Don't forget to send your bug reports to them... |
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