3 * Copyright 2003 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
28 // issue a stop bus cycle and wait for completion
31 // returns non-zero if successful, else 0
33 i2c_read (unsigned char addr, xdata unsigned char *buf, unsigned char len)
35 volatile unsigned char junk;
37 if (len == 0) // reading zero bytes always works
40 // memset (buf, 0, len); // FIXME, remove
42 while (I2CS & bmSTOP) // wait for stop to clear
47 I2DAT = (addr << 1) | 1; // write address and direction (1's the read bit)
49 while ((I2CS & bmDONE) == 0)
52 if ((I2CS & bmBERR) || (I2CS & bmACK) == 0) // no device answered...
58 junk = I2DAT; // trigger the first read cycle
62 while ((I2CS & bmDONE) == 0)
72 *buf++ = I2DAT; // get data, trigger another read
76 // wait for final byte
78 while ((I2CS & bmDONE) == 0)
96 // returns non-zero if successful, else 0
98 i2c_write (unsigned char addr, xdata const unsigned char *buf, unsigned char len)
100 while (I2CS & bmSTOP) // wait for stop to clear
104 I2DAT = (addr << 1) | 0; // write address and direction (0's the write bit)
106 while ((I2CS & bmDONE) == 0)
109 if ((I2CS & bmBERR) || (I2CS & bmACK) == 0) // no device answered...
116 while ((I2CS & bmDONE) == 0)
119 if ((I2CS & bmBERR) || (I2CS & bmACK) == 0) // no device answered...