diff options
Diffstat (limited to 'gcell/src/lib/runtime/spu/gc_delay.c')
-rw-r--r-- | gcell/src/lib/runtime/spu/gc_delay.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/gcell/src/lib/runtime/spu/gc_delay.c b/gcell/src/lib/runtime/spu/gc_delay.c new file mode 100644 index 000000000..21ee587f8 --- /dev/null +++ b/gcell/src/lib/runtime/spu/gc_delay.c @@ -0,0 +1,58 @@ +/* -*- c++ -*- */ +/* + * Copyright 2007 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "gc_delay.h" +#include <compiler.h> + +inline static void +gc_udelay_1us(void) +{ + unsigned int i = 158; + + do { // 20 clocks per iteration of the loop + asm ("nop $127; nop $127; nop $127; nop $127; nop $127"); + asm ("nop $127; nop $127; nop $127; nop $127; nop $127"); + asm ("nop $127; nop $127; nop $127; nop $127; nop $127"); + asm ("nop $127; nop $127"); + } while(--i != 0); +} + +void +gc_udelay(unsigned int usecs) +{ + unsigned int i; + for (i = 0; i < usecs; i++) + gc_udelay_1us(); +} + +void +gc_cdelay(unsigned int cpu_cycles) +{ + if (cpu_cycles < 40) // roughly the amount of overhead + return; + + cpu_cycles >>= 2; // about 4 cycles / loop + + while (cpu_cycles-- != 0){ + asm ("nop $127"); // keeps compiler from removing the loop + } +} + |