Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

targets/TARGET_NXP/TARGET_LPC43XX/analogout_api.c@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 *
elessair 0:f269e3021894 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
elessair 0:f269e3021894 17 */
elessair 0:f269e3021894 18 #include "mbed_assert.h"
elessair 0:f269e3021894 19 #include "analogout_api.h"
elessair 0:f269e3021894 20
elessair 0:f269e3021894 21 #include "cmsis.h"
elessair 0:f269e3021894 22 #include "pinmap.h"
elessair 0:f269e3021894 23 #include "mbed_error.h"
elessair 0:f269e3021894 24 #include "gpio_api.h"
elessair 0:f269e3021894 25
elessair 0:f269e3021894 26 static const PinMap PinMap_DAC[] = {
elessair 0:f269e3021894 27 #ifdef TARGET_LPC4337
elessair 0:f269e3021894 28 {P4_3, DAC_0, 0},
elessair 0:f269e3021894 29 #else
elessair 0:f269e3021894 30 {P4_4, DAC_0, 0},
elessair 0:f269e3021894 31 #endif
elessair 0:f269e3021894 32 {NC, NC, 0}
elessair 0:f269e3021894 33 };
elessair 0:f269e3021894 34
elessair 0:f269e3021894 35 void analogout_init(dac_t *obj, PinName pin) {
elessair 0:f269e3021894 36 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
elessair 0:f269e3021894 37 MBED_ASSERT(obj->dac != (DACName)NC);
elessair 0:f269e3021894 38
elessair 0:f269e3021894 39 // Reset pin function to GPIO
elessair 0:f269e3021894 40 gpio_set(pin);
elessair 0:f269e3021894 41 // Select DAC on analog function select register in SCU
elessair 0:f269e3021894 42 LPC_SCU->ENAIO[2] |= 1; // Sets pin as DAC
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 // Set bias=0 for maximum DAC update rate (1 MHz)
elessair 0:f269e3021894 45 LPC_DAC->CR &= ~DAC_BIAS_EN;
elessair 0:f269e3021894 46 // Enable DAC and DMA
elessair 0:f269e3021894 47 LPC_DAC->CTRL |= DAC_DMA_ENA;
elessair 0:f269e3021894 48
elessair 0:f269e3021894 49 analogout_write_u16(obj, 0);
elessair 0:f269e3021894 50 }
elessair 0:f269e3021894 51
elessair 0:f269e3021894 52 void analogout_free(dac_t *obj) {}
elessair 0:f269e3021894 53
elessair 0:f269e3021894 54 static inline void dac_write(int value) {
elessair 0:f269e3021894 55
elessair 0:f269e3021894 56 // Set the DAC output
elessair 0:f269e3021894 57 LPC_DAC->CR = DAC_SET(value);
elessair 0:f269e3021894 58 }
elessair 0:f269e3021894 59
elessair 0:f269e3021894 60 static inline int dac_read() {
elessair 0:f269e3021894 61 return (DAC_GET(LPC_DAC->CR));
elessair 0:f269e3021894 62 }
elessair 0:f269e3021894 63
elessair 0:f269e3021894 64 void analogout_write(dac_t *obj, float value) {
elessair 0:f269e3021894 65 if (value < 0.0f) {
elessair 0:f269e3021894 66 dac_write(0);
elessair 0:f269e3021894 67 } else if (value > 1.0f) {
elessair 0:f269e3021894 68 dac_write(DAC_RANGE);
elessair 0:f269e3021894 69 } else {
elessair 0:f269e3021894 70 dac_write(value * (float)DAC_RANGE);
elessair 0:f269e3021894 71 }
elessair 0:f269e3021894 72 }
elessair 0:f269e3021894 73
elessair 0:f269e3021894 74 void analogout_write_u16(dac_t *obj, uint16_t value) {
elessair 0:f269e3021894 75 dac_write(value >> 6); // 10-bit
elessair 0:f269e3021894 76 }
elessair 0:f269e3021894 77
elessair 0:f269e3021894 78 float analogout_read(dac_t *obj) {
elessair 0:f269e3021894 79 uint32_t value = dac_read();
elessair 0:f269e3021894 80 return (float)value * (1.0f / (float)DAC_RANGE);
elessair 0:f269e3021894 81 }
elessair 0:f269e3021894 82
elessair 0:f269e3021894 83 uint16_t analogout_read_u16(dac_t *obj) {
elessair 0:f269e3021894 84 uint32_t value = dac_read(); // 10-bit
elessair 0:f269e3021894 85 return (value << 6) | ((value >> 4) & 0x003F);
elessair 0:f269e3021894 86 }