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[/] [gecko3/] [trunk/] [GECKO3COM/] [gecko3com-fw/] [firmware/] [lib/] [delay.c] - Blame information for rev 32

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Line No. Rev Author Line
1 9 nussgipfel
/* -*- c++ -*- */
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/*
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 * Copyright 2003 Free Software Foundation, Inc.
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 *
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 * This file is part of GNU Radio
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 *
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 * GNU Radio is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 3, or (at your option)
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 * any later version.
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 *
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 * GNU Radio is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with GNU Radio; see the file COPYING.  If not, write to
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 * the Free Software Foundation, Inc., 51 Franklin Street,
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 * Boston, MA 02110-1301, USA.
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 */
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/*
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 * Delay approximately 1 microsecond (including overhead in udelay).
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 */
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static void
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udelay1 (void) _naked
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{
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  _asm                          ; lcall that got us here took 4 bus cycles
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        ret                     ; 4 bus cycles
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  _endasm;
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}
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/*
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 * delay for approximately usecs microseconds
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 */
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void
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udelay (unsigned char usecs)
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{
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  do {
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    udelay1 ();
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  } while (--usecs != 0);
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}
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/*
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 * Delay approximately 1 millisecond.
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 * We're running at 48 MHz, so we need 48,000 clock cycles.
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 *
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 * Note however, that each bus cycle takes 4 clock cycles (not obvious,
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 * but explains the factor of 4 problem below).
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 */
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static void
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mdelay1 (void) _naked
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{
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  _asm
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        mov     dptr,#(-1200 & 0xffff)
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002$:
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        inc     dptr            ; 3 bus cycles
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        mov     a, dpl          ; 2 bus cycles
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        orl     a, dph          ; 2 bus cycles
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        jnz     002$            ; 3 bus cycles
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        ret
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  _endasm;
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}
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void
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mdelay (unsigned int msecs)
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{
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  do {
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    mdelay1 ();
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  } while (--msecs != 0);
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}
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