Umar Naeem / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by Umar Naeem

targets/TARGET_NXP/TARGET_LPC43XX/analogout_api.c@165:2dd56e6daeec, 2017-05-23 (annotated)

Committer:
ranaumarnaeem
Date:
Tue May 23 12:54:50 2017 +0000
Revision:
165:2dd56e6daeec
Parent:
149:156823d33999 
jhjg

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 *
<> 144:ef7eb2e8f9f7 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
<> 144:ef7eb2e8f9f7 17 */
<> 144:ef7eb2e8f9f7 18 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 19 #include "analogout_api.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 22 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 23 #include "mbed_error.h"
<> 144:ef7eb2e8f9f7 24 #include "gpio_api.h"
<> 144:ef7eb2e8f9f7 25
<> 144:ef7eb2e8f9f7 26 static const PinMap PinMap_DAC[] = {
<> 144:ef7eb2e8f9f7 27 #ifdef TARGET_LPC4337
<> 144:ef7eb2e8f9f7 28 {P4_3, DAC_0, 0},
<> 144:ef7eb2e8f9f7 29 #else
<> 144:ef7eb2e8f9f7 30 {P4_4, DAC_0, 0},
<> 144:ef7eb2e8f9f7 31 #endif
<> 144:ef7eb2e8f9f7 32 {NC, NC, 0}
<> 144:ef7eb2e8f9f7 33 };
<> 144:ef7eb2e8f9f7 34
<> 144:ef7eb2e8f9f7 35 void analogout_init(dac_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 36 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 37 MBED_ASSERT(obj->dac != (DACName)NC);
<> 144:ef7eb2e8f9f7 38
<> 144:ef7eb2e8f9f7 39 // Reset pin function to GPIO
<> 144:ef7eb2e8f9f7 40 gpio_set(pin);
<> 144:ef7eb2e8f9f7 41 // Select DAC on analog function select register in SCU
<> 144:ef7eb2e8f9f7 42 LPC_SCU->ENAIO[2] |= 1; // Sets pin as DAC
<> 144:ef7eb2e8f9f7 43
<> 144:ef7eb2e8f9f7 44 // Set bias=0 for maximum DAC update rate (1 MHz)
<> 144:ef7eb2e8f9f7 45 LPC_DAC->CR &= ~DAC_BIAS_EN;
<> 144:ef7eb2e8f9f7 46 // Enable DAC and DMA
<> 144:ef7eb2e8f9f7 47 LPC_DAC->CTRL |= DAC_DMA_ENA;
<> 144:ef7eb2e8f9f7 48
<> 144:ef7eb2e8f9f7 49 analogout_write_u16(obj, 0);
<> 144:ef7eb2e8f9f7 50 }
<> 144:ef7eb2e8f9f7 51
<> 144:ef7eb2e8f9f7 52 void analogout_free(dac_t *obj) {}
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 static inline void dac_write(int value) {
<> 144:ef7eb2e8f9f7 55
<> 144:ef7eb2e8f9f7 56 // Set the DAC output
<> 144:ef7eb2e8f9f7 57 LPC_DAC->CR = DAC_SET(value);
<> 144:ef7eb2e8f9f7 58 }
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 static inline int dac_read() {
<> 144:ef7eb2e8f9f7 61 return (DAC_GET(LPC_DAC->CR));
<> 144:ef7eb2e8f9f7 62 }
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 void analogout_write(dac_t *obj, float value) {
<> 144:ef7eb2e8f9f7 65 if (value < 0.0f) {
<> 144:ef7eb2e8f9f7 66 dac_write(0);
<> 144:ef7eb2e8f9f7 67 } else if (value > 1.0f) {
<> 144:ef7eb2e8f9f7 68 dac_write(DAC_RANGE);
<> 144:ef7eb2e8f9f7 69 } else {
<> 144:ef7eb2e8f9f7 70 dac_write(value * (float)DAC_RANGE);
<> 144:ef7eb2e8f9f7 71 }
<> 144:ef7eb2e8f9f7 72 }
<> 144:ef7eb2e8f9f7 73
<> 144:ef7eb2e8f9f7 74 void analogout_write_u16(dac_t *obj, uint16_t value) {
<> 144:ef7eb2e8f9f7 75 dac_write(value >> 6); // 10-bit
<> 144:ef7eb2e8f9f7 76 }
<> 144:ef7eb2e8f9f7 77
<> 144:ef7eb2e8f9f7 78 float analogout_read(dac_t *obj) {
<> 144:ef7eb2e8f9f7 79 uint32_t value = dac_read();
<> 144:ef7eb2e8f9f7 80 return (float)value * (1.0f / (float)DAC_RANGE);
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 uint16_t analogout_read_u16(dac_t *obj) {
<> 144:ef7eb2e8f9f7 84 uint32_t value = dac_read(); // 10-bit
<> 144:ef7eb2e8f9f7 85 return (value << 6) | ((value >> 4) & 0x003F);
<> 144:ef7eb2e8f9f7 86 }