Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Freescale/TARGET_K20XX/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) 2006-2015 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
<> 144:ef7eb2e8f9f7 17 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 18 #include "analogout_api.h"
<> 144:ef7eb2e8f9f7 19
<> 144:ef7eb2e8f9f7 20 #if DEVICE_ANALOGOUT
<> 144:ef7eb2e8f9f7 21
<> 144:ef7eb2e8f9f7 22 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 23 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 24 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 25
<> 144:ef7eb2e8f9f7 26 #define RANGE_12BIT 0xFFF
<> 144:ef7eb2e8f9f7 27
<> 144:ef7eb2e8f9f7 28 void analogout_init(dac_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 29 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 30 MBED_ASSERT(obj->dac != (DACName)NC);
<> 144:ef7eb2e8f9f7 31
<> 144:ef7eb2e8f9f7 32 SIM->SCGC2 |= SIM_SCGC2_DAC0_MASK;
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 uint32_t port = (uint32_t)pin >> PORT_SHIFT;
<> 144:ef7eb2e8f9f7 35 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
<> 144:ef7eb2e8f9f7 36
<> 144:ef7eb2e8f9f7 37 DAC0->DAT[obj->dac].DATH = 0;
<> 144:ef7eb2e8f9f7 38 DAC0->DAT[obj->dac].DATL = 0;
<> 144:ef7eb2e8f9f7 39
<> 144:ef7eb2e8f9f7 40 DAC0->C1 = DAC_C1_DACBFMD_MASK; // One-Time Scan Mode
<> 144:ef7eb2e8f9f7 41
<> 144:ef7eb2e8f9f7 42 DAC0->C0 = DAC_C0_DACEN_MASK // Enable
<> 144:ef7eb2e8f9f7 43 | DAC_C0_DACSWTRG_MASK // Software Trigger
<> 144:ef7eb2e8f9f7 44 | DAC_C0_DACRFS_MASK; // VDDA selected
<> 144:ef7eb2e8f9f7 45
<> 144:ef7eb2e8f9f7 46 analogout_write_u16(obj, 0);
<> 144:ef7eb2e8f9f7 47 }
<> 144:ef7eb2e8f9f7 48
<> 144:ef7eb2e8f9f7 49 void analogout_free(dac_t *obj) {}
<> 144:ef7eb2e8f9f7 50
<> 144:ef7eb2e8f9f7 51 static inline void dac_write(dac_t *obj, int value) {
<> 144:ef7eb2e8f9f7 52 DAC0->DAT[obj->dac].DATL = (uint8_t)( value & 0xFF);
<> 144:ef7eb2e8f9f7 53 DAC0->DAT[obj->dac].DATH = (uint8_t)((value >> 8) & 0xFF);
<> 144:ef7eb2e8f9f7 54 }
<> 144:ef7eb2e8f9f7 55
<> 144:ef7eb2e8f9f7 56 static inline int dac_read(dac_t *obj) {
<> 144:ef7eb2e8f9f7 57 return ((DAC0->DAT[obj->dac].DATH << 8) | DAC0->DAT[obj->dac].DATL);
<> 144:ef7eb2e8f9f7 58 }
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 void analogout_write(dac_t *obj, float value) {
<> 144:ef7eb2e8f9f7 61 if (value < 0.0) {
<> 144:ef7eb2e8f9f7 62 dac_write(obj, 0);
<> 144:ef7eb2e8f9f7 63 } else if (value > 1.0) {
<> 144:ef7eb2e8f9f7 64 dac_write(obj, RANGE_12BIT);
<> 144:ef7eb2e8f9f7 65 } else {
<> 144:ef7eb2e8f9f7 66 dac_write(obj, value * (float)RANGE_12BIT);
<> 144:ef7eb2e8f9f7 67 }
<> 144:ef7eb2e8f9f7 68 }
<> 144:ef7eb2e8f9f7 69
<> 144:ef7eb2e8f9f7 70 void analogout_write_u16(dac_t *obj, uint16_t value) {
<> 144:ef7eb2e8f9f7 71 dac_write(obj, value >> 4); // 12-bit
<> 144:ef7eb2e8f9f7 72 }
<> 144:ef7eb2e8f9f7 73
<> 144:ef7eb2e8f9f7 74 float analogout_read(dac_t *obj) {
<> 144:ef7eb2e8f9f7 75 uint32_t value = dac_read(obj);
<> 144:ef7eb2e8f9f7 76 return (float)value * (1.0f / (float)RANGE_12BIT);
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 uint16_t analogout_read_u16(dac_t *obj) {
<> 144:ef7eb2e8f9f7 80 uint32_t value = dac_read(obj); // 12-bit
<> 144:ef7eb2e8f9f7 81 return (value << 4) | ((value >> 8) & 0x003F);
<> 144:ef7eb2e8f9f7 82 }
<> 144:ef7eb2e8f9f7 83
<> 144:ef7eb2e8f9f7 84 #endif