3 * adcopen - initialize AD module
5 * written by Vangelis Rokas, 2004 <vrokas AT otenet.gr>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * This library 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 this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 #include <pic18fregs.h>
27 * channel: one of ADC_CHN_*
28 * fosc: one of ADC_FOSC_*
29 * pcfg: one of ADC_CFG_* (a bitmask with set bits denoting digital ports for 242-style)
30 * config: ADC_FRM_* | ADC_INT_* | ADC_VCFG_*
33 void adc_open(unsigned char channel, unsigned char fosc, unsigned char pcfg, unsigned char config)
38 #if defined(__SDCC_ADC_STYLE242)
39 ADCON0 = ((channel & 0x07) << 3) | ((fosc & 0x03) << 6);
40 ADCON1 = (pcfg & 0x0f) | (config & ADC_FRM_RJUST);
44 #elif defined (__SDCC_ADC_STYLE1220)
45 ADCON0 = ((channel & 0x07) | (config & ADC_VCFG_AN3_AN2)) << 2;
46 ADCON1 = (pcfg & 0x7f);
47 ADCON2 = (ADCON2 & 0x38) | (fosc & 0x07) | (config & ADC_FRM_RJUST);
48 #elif defined(__SDCC_ADC_STYLE2220)
49 ADCON0 = (channel & 0x0f) << 2;
50 /* XXX: Should be (pcfg & 0x0f) as VCFG comes from config,
51 * but we retain compatibility for now ... */
52 ADCON1 = (pcfg & 0x3f) | (config & ADC_VCFG_AN3_AN2);
53 ADCON2 = (ADCON2 & 0x38) | (fosc & 0x07) | (config & ADC_FRM_RJUST);
54 #else /* unsupported ADC style */
55 #error Unsupported ADC style.
58 if (config & ADC_INT_ON) {
64 /* enable the A/D module */