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53 lines
1.2 KiB
Groff
53 lines
1.2 KiB
Groff
4 years ago
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.TH "<util/parity.h>: Parity bit generation" 3 "24 Jun 2019" "Version 2.0.0" "avr-libc" \" -*- nroff -*-
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.ad l
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.nh
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.SH NAME
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<util/parity.h>: Parity bit generation \-
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.SS "Defines"
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.in +1c
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.ti -1c
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.RI "#define \fBparity_even_bit\fP(val)"
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.br
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.in -1c
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.SH "Detailed Description"
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.PP
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.PP
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.nf
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#include <util/parity.h>
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.fi
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.PP
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.PP
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This header file contains optimized assembler code to calculate the parity bit for a byte.
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.SH "Define Documentation"
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.PP
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.SS "#define parity_even_bit(val)"\fBValue:\fP
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.PP
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.nf
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(__extension__({ \
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unsigned char __t; \
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__asm__ ( \
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'mov __tmp_reg__,%0' '\n\t' \
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'swap %0' '\n\t' \
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'eor %0,__tmp_reg__' '\n\t' \
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'mov __tmp_reg__,%0' '\n\t' \
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'lsr %0' '\n\t' \
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'lsr %0' '\n\t' \
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'eor %0,__tmp_reg__' \
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: '=r' (__t) \
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: '0' ((unsigned char)(val)) \
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: 'r0' \
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); \
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(((__t + 1) >> 1) & 1); \
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}))
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.fi
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\fBReturns:\fP
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.RS 4
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1 if \fCval\fP has an odd number of bits set.
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.RE
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.PP
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.SH "Author"
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.PP
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Generated automatically by Doxygen for avr-libc from the source code.
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