diff options
author | Josh Blum <josh@joshknows.com> | 2010-11-05 13:53:39 -0700 |
---|---|---|
committer | Josh Blum <josh@joshknows.com> | 2010-11-05 13:53:39 -0700 |
commit | 3ac3457184bc3b251ce7398eee56c931983abe65 (patch) | |
tree | 7cfa1ba616788ad083236272a323c3a6e2964da3 /firmware/fx2/common/delay.c | |
parent | 144ebf29327981db8422049b451852744619678d (diff) | |
parent | c473cc56fafcb47d6ba1f16e8c9fb89ff6c57bca (diff) | |
download | uhd-3ac3457184bc3b251ce7398eee56c931983abe65.tar.gz uhd-3ac3457184bc3b251ce7398eee56c931983abe65.tar.bz2 uhd-3ac3457184bc3b251ce7398eee56c931983abe65.zip |
Merge branch 'good_stuff' into mb_eeprom
Conflicts:
firmware/fx2/include
Diffstat (limited to 'firmware/fx2/common/delay.c')
-rw-r--r-- | firmware/fx2/common/delay.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/firmware/fx2/common/delay.c b/firmware/fx2/common/delay.c new file mode 100644 index 000000000..13cf0eec8 --- /dev/null +++ b/firmware/fx2/common/delay.c @@ -0,0 +1,76 @@ +/* -*- c++ -*- */ +/* + * Copyright 2003 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 GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +/* + * Delay approximately 1 microsecond (including overhead in udelay). + */ +static void +udelay1 (void) _naked +{ + _asm ; lcall that got us here took 4 bus cycles + ret ; 4 bus cycles + _endasm; +} + +/* + * delay for approximately usecs microseconds + */ +void +udelay (unsigned char usecs) +{ + do { + udelay1 (); + } while (--usecs != 0); +} + + +/* + * Delay approximately 1 millisecond. + * We're running at 48 MHz, so we need 48,000 clock cycles. + * + * Note however, that each bus cycle takes 4 clock cycles (not obvious, + * but explains the factor of 4 problem below). + */ +static void +mdelay1 (void) _naked +{ + _asm + mov dptr,#(-1200 & 0xffff) +002$: + inc dptr ; 3 bus cycles + mov a, dpl ; 2 bus cycles + orl a, dph ; 2 bus cycles + jnz 002$ ; 3 bus cycles + + ret + _endasm; +} + +void +mdelay (unsigned int msecs) +{ + do { + mdelay1 (); + } while (--msecs != 0); +} + + |