Umar Naeem / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by Umar Naeem

targets/TARGET_NXP/TARGET_LPC176X/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 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "analogout_api.h"
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 20 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 21
<> 144:ef7eb2e8f9f7 22 static const PinMap PinMap_DAC[] = {
<> 144:ef7eb2e8f9f7 23 {P0_26, DAC_0, 2},
<> 144:ef7eb2e8f9f7 24 {NC , NC , 0}
<> 144:ef7eb2e8f9f7 25 };
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 void analogout_init(dac_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 28 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 29 MBED_ASSERT(obj->dac != (DACName)NC);
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 // power is on by default, set DAC clk divider is /4
<> 144:ef7eb2e8f9f7 32 LPC_SC->PCLKSEL0 &= ~(0x3 << 22);
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 // map out (must be done before accessing registers)
<> 144:ef7eb2e8f9f7 35 pinmap_pinout(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 36
<> 144:ef7eb2e8f9f7 37 analogout_write_u16(obj, 0);
<> 144:ef7eb2e8f9f7 38 }
<> 144:ef7eb2e8f9f7 39
<> 144:ef7eb2e8f9f7 40 void analogout_free(dac_t *obj) {}
<> 144:ef7eb2e8f9f7 41
<> 144:ef7eb2e8f9f7 42 static inline void dac_write(int value) {
<> 144:ef7eb2e8f9f7 43 value &= 0x3FF; // 10-bit
<> 144:ef7eb2e8f9f7 44
<> 144:ef7eb2e8f9f7 45 // Set the DAC output
<> 144:ef7eb2e8f9f7 46 LPC_DAC->DACR = (0 << 16) // bias = 0
<> 144:ef7eb2e8f9f7 47 | (value << 6);
<> 144:ef7eb2e8f9f7 48 }
<> 144:ef7eb2e8f9f7 49
<> 144:ef7eb2e8f9f7 50 static inline int dac_read() {
<> 144:ef7eb2e8f9f7 51 return (LPC_DAC->DACR >> 6) & 0x3FF;
<> 144:ef7eb2e8f9f7 52 }
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 void analogout_write(dac_t *obj, float value) {
<> 144:ef7eb2e8f9f7 55 if (value < 0.0f) {
<> 144:ef7eb2e8f9f7 56 dac_write(0);
<> 144:ef7eb2e8f9f7 57 } else if (value > 1.0f) {
<> 144:ef7eb2e8f9f7 58 dac_write(0x3FF);
<> 144:ef7eb2e8f9f7 59 } else {
<> 144:ef7eb2e8f9f7 60 dac_write(value * (float)0x3FF);
<> 144:ef7eb2e8f9f7 61 }
<> 144:ef7eb2e8f9f7 62 }
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 void analogout_write_u16(dac_t *obj, uint16_t value) {
<> 144:ef7eb2e8f9f7 65 dac_write(value >> 6); // 10-bit
<> 144:ef7eb2e8f9f7 66 }
<> 144:ef7eb2e8f9f7 67
<> 144:ef7eb2e8f9f7 68 float analogout_read(dac_t *obj) {
<> 144:ef7eb2e8f9f7 69 uint32_t value = dac_read();
<> 144:ef7eb2e8f9f7 70 return (float)value * (1.0f / (float)0x3FF);
<> 144:ef7eb2e8f9f7 71 }
<> 144:ef7eb2e8f9f7 72
<> 144:ef7eb2e8f9f7 73 uint16_t analogout_read_u16(dac_t *obj) {
<> 144:ef7eb2e8f9f7 74 uint32_t value = dac_read(); // 10-bit
<> 144:ef7eb2e8f9f7 75 return (value << 6) | ((value >> 4) & 0x003F);
<> 144:ef7eb2e8f9f7 76 }