Johannes Stratmann / mbed-dev

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targets/hal/TARGET_NXP/TARGET_LPC43XX/analogout_api.c@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
144:ef7eb2e8f9f7 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

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 }