Joris Aerts / mbed-src

mbed library sources

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targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c@19:398f4c622e1b, 2013-08-19 (annotated)

Committer:
bogdanm
Date:
Mon Aug 19 18:17:02 2013 +0300
Revision:
19:398f4c622e1b
Parent:
13:0645d8841f51
Child:
227:7bd0639b8911
Sync with official mbed library release 66

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 10:3bc89ef62ce7 1 /* mbed Microcontroller Library
emilmont 10:3bc89ef62ce7 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 10:3bc89ef62ce7 3 *
emilmont 10:3bc89ef62ce7 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 10:3bc89ef62ce7 5 * you may not use this file except in compliance with the License.
emilmont 10:3bc89ef62ce7 6 * You may obtain a copy of the License at
emilmont 10:3bc89ef62ce7 7 *
emilmont 10:3bc89ef62ce7 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 10:3bc89ef62ce7 9 *
emilmont 10:3bc89ef62ce7 10 * Unless required by applicable law or agreed to in writing, software
emilmont 10:3bc89ef62ce7 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 10:3bc89ef62ce7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 10:3bc89ef62ce7 13 * See the License for the specific language governing permissions and
emilmont 10:3bc89ef62ce7 14 * limitations under the License.
emilmont 10:3bc89ef62ce7 15 */
emilmont 10:3bc89ef62ce7 16 #include "analogout_api.h"
emilmont 10:3bc89ef62ce7 17
emilmont 10:3bc89ef62ce7 18 #include "cmsis.h"
emilmont 10:3bc89ef62ce7 19 #include "pinmap.h"
emilmont 10:3bc89ef62ce7 20 #include "error.h"
emilmont 10:3bc89ef62ce7 21
emilmont 10:3bc89ef62ce7 22 static const PinMap PinMap_DAC[] = {
emilmont 10:3bc89ef62ce7 23 {P0_26, DAC_0, 2},
emilmont 10:3bc89ef62ce7 24 {NC , NC , 0}
emilmont 10:3bc89ef62ce7 25 };
emilmont 10:3bc89ef62ce7 26
emilmont 10:3bc89ef62ce7 27 void analogout_init(dac_t *obj, PinName pin) {
emilmont 10:3bc89ef62ce7 28 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
bogdanm 19:398f4c622e1b 29 if (obj->dac == (DACName)NC) {
emilmont 10:3bc89ef62ce7 30 error("DAC pin mapping failed");
emilmont 10:3bc89ef62ce7 31 }
emilmont 10:3bc89ef62ce7 32
emilmont 10:3bc89ef62ce7 33 // power is on by default, set DAC clk divider is /4
emilmont 10:3bc89ef62ce7 34 LPC_SC->PCLKSEL0 &= ~(0x3 << 22);
emilmont 10:3bc89ef62ce7 35
emilmont 10:3bc89ef62ce7 36 // map out (must be done before accessing registers)
emilmont 10:3bc89ef62ce7 37 pinmap_pinout(pin, PinMap_DAC);
emilmont 10:3bc89ef62ce7 38
emilmont 10:3bc89ef62ce7 39 analogout_write_u16(obj, 0);
emilmont 10:3bc89ef62ce7 40 }
emilmont 10:3bc89ef62ce7 41
emilmont 10:3bc89ef62ce7 42 void analogout_free(dac_t *obj) {}
emilmont 10:3bc89ef62ce7 43
emilmont 10:3bc89ef62ce7 44 static inline void dac_write(int value) {
emilmont 10:3bc89ef62ce7 45 value &= 0x3FF; // 10-bit
emilmont 10:3bc89ef62ce7 46
emilmont 10:3bc89ef62ce7 47 // Set the DAC output
emilmont 10:3bc89ef62ce7 48 LPC_DAC->DACR = (0 << 16) // bias = 0
emilmont 10:3bc89ef62ce7 49 | (value << 6);
emilmont 10:3bc89ef62ce7 50 }
emilmont 10:3bc89ef62ce7 51
emilmont 10:3bc89ef62ce7 52 static inline int dac_read() {
emilmont 10:3bc89ef62ce7 53 return (LPC_DAC->DACR >> 6) & 0x3FF;
emilmont 10:3bc89ef62ce7 54 }
emilmont 10:3bc89ef62ce7 55
emilmont 10:3bc89ef62ce7 56 void analogout_write(dac_t *obj, float value) {
emilmont 10:3bc89ef62ce7 57 if (value < 0.0f) {
emilmont 10:3bc89ef62ce7 58 dac_write(0);
emilmont 10:3bc89ef62ce7 59 } else if (value > 1.0f) {
emilmont 10:3bc89ef62ce7 60 dac_write(0x3FF);
emilmont 10:3bc89ef62ce7 61 } else {
emilmont 10:3bc89ef62ce7 62 dac_write(value * (float)0x3FF);
emilmont 10:3bc89ef62ce7 63 }
emilmont 10:3bc89ef62ce7 64 }
emilmont 10:3bc89ef62ce7 65
emilmont 10:3bc89ef62ce7 66 void analogout_write_u16(dac_t *obj, uint16_t value) {
emilmont 10:3bc89ef62ce7 67 dac_write(value >> 6); // 10-bit
emilmont 10:3bc89ef62ce7 68 }
emilmont 10:3bc89ef62ce7 69
emilmont 10:3bc89ef62ce7 70 float analogout_read(dac_t *obj) {
emilmont 10:3bc89ef62ce7 71 uint32_t value = dac_read();
emilmont 10:3bc89ef62ce7 72 return (float)value * (1.0f / (float)0x3FF);
emilmont 10:3bc89ef62ce7 73 }
emilmont 10:3bc89ef62ce7 74
emilmont 10:3bc89ef62ce7 75 uint16_t analogout_read_u16(dac_t *obj) {
emilmont 10:3bc89ef62ce7 76 uint32_t value = dac_read(); // 10-bit
emilmont 10:3bc89ef62ce7 77 return (value << 6) | ((value >> 4) & 0x003F);
emilmont 10:3bc89ef62ce7 78 }