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@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
144:ef7eb2e8f9f7
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /* mbed Microcontroller Library
bogdanm 0:9b334a45a8ff 2 * Copyright (c) 2006-2015 ARM Limited
bogdanm 0:9b334a45a8ff 3 *
bogdanm 0:9b334a45a8ff 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 0:9b334a45a8ff 5 * you may not use this file except in compliance with the License.
bogdanm 0:9b334a45a8ff 6 * You may obtain a copy of the License at
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 0:9b334a45a8ff 9 *
bogdanm 0:9b334a45a8ff 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 0:9b334a45a8ff 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 0:9b334a45a8ff 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 0:9b334a45a8ff 13 * See the License for the specific language governing permissions and
bogdanm 0:9b334a45a8ff 14 * limitations under the License.
bogdanm 0:9b334a45a8ff 15 */
bogdanm 0:9b334a45a8ff 16
bogdanm 0:9b334a45a8ff 17 #include "mbed_assert.h"
bogdanm 0:9b334a45a8ff 18 #include "analogout_api.h"
bogdanm 0:9b334a45a8ff 19
bogdanm 0:9b334a45a8ff 20 #if DEVICE_ANALOGOUT
bogdanm 0:9b334a45a8ff 21
bogdanm 0:9b334a45a8ff 22 #include "cmsis.h"
bogdanm 0:9b334a45a8ff 23 #include "pinmap.h"
bogdanm 0:9b334a45a8ff 24 #include "PeripheralPins.h"
bogdanm 0:9b334a45a8ff 25
bogdanm 0:9b334a45a8ff 26 #define RANGE_12BIT 0xFFF
bogdanm 0:9b334a45a8ff 27
bogdanm 0:9b334a45a8ff 28 void analogout_init(dac_t *obj, PinName pin) {
bogdanm 0:9b334a45a8ff 29 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
bogdanm 0:9b334a45a8ff 30 MBED_ASSERT(obj->dac != (DACName)NC);
bogdanm 0:9b334a45a8ff 31
bogdanm 0:9b334a45a8ff 32 SIM->SCGC2 |= SIM_SCGC2_DAC0_MASK;
bogdanm 0:9b334a45a8ff 33
bogdanm 0:9b334a45a8ff 34 uint32_t port = (uint32_t)pin >> PORT_SHIFT;
bogdanm 0:9b334a45a8ff 35 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
bogdanm 0:9b334a45a8ff 36
bogdanm 0:9b334a45a8ff 37 DAC0->DAT[obj->dac].DATH = 0;
bogdanm 0:9b334a45a8ff 38 DAC0->DAT[obj->dac].DATL = 0;
bogdanm 0:9b334a45a8ff 39
bogdanm 0:9b334a45a8ff 40 DAC0->C1 = DAC_C1_DACBFMD_MASK; // One-Time Scan Mode
bogdanm 0:9b334a45a8ff 41
bogdanm 0:9b334a45a8ff 42 DAC0->C0 = DAC_C0_DACEN_MASK // Enable
bogdanm 0:9b334a45a8ff 43 | DAC_C0_DACSWTRG_MASK // Software Trigger
bogdanm 0:9b334a45a8ff 44 | DAC_C0_DACRFS_MASK; // VDDA selected
bogdanm 0:9b334a45a8ff 45
bogdanm 0:9b334a45a8ff 46 analogout_write_u16(obj, 0);
bogdanm 0:9b334a45a8ff 47 }
bogdanm 0:9b334a45a8ff 48
bogdanm 0:9b334a45a8ff 49 void analogout_free(dac_t *obj) {}
bogdanm 0:9b334a45a8ff 50
bogdanm 0:9b334a45a8ff 51 static inline void dac_write(dac_t *obj, int value) {
bogdanm 0:9b334a45a8ff 52 DAC0->DAT[obj->dac].DATL = (uint8_t)( value & 0xFF);
bogdanm 0:9b334a45a8ff 53 DAC0->DAT[obj->dac].DATH = (uint8_t)((value >> 8) & 0xFF);
bogdanm 0:9b334a45a8ff 54 }
bogdanm 0:9b334a45a8ff 55
bogdanm 0:9b334a45a8ff 56 static inline int dac_read(dac_t *obj) {
bogdanm 0:9b334a45a8ff 57 return ((DAC0->DAT[obj->dac].DATH << 8) | DAC0->DAT[obj->dac].DATL);
bogdanm 0:9b334a45a8ff 58 }
bogdanm 0:9b334a45a8ff 59
bogdanm 0:9b334a45a8ff 60 void analogout_write(dac_t *obj, float value) {
bogdanm 0:9b334a45a8ff 61 if (value < 0.0) {
bogdanm 0:9b334a45a8ff 62 dac_write(obj, 0);
bogdanm 0:9b334a45a8ff 63 } else if (value > 1.0) {
bogdanm 0:9b334a45a8ff 64 dac_write(obj, RANGE_12BIT);
bogdanm 0:9b334a45a8ff 65 } else {
bogdanm 0:9b334a45a8ff 66 dac_write(obj, value * (float)RANGE_12BIT);
bogdanm 0:9b334a45a8ff 67 }
bogdanm 0:9b334a45a8ff 68 }
bogdanm 0:9b334a45a8ff 69
bogdanm 0:9b334a45a8ff 70 void analogout_write_u16(dac_t *obj, uint16_t value) {
bogdanm 0:9b334a45a8ff 71 dac_write(obj, value >> 4); // 12-bit
bogdanm 0:9b334a45a8ff 72 }
bogdanm 0:9b334a45a8ff 73
bogdanm 0:9b334a45a8ff 74 float analogout_read(dac_t *obj) {
bogdanm 0:9b334a45a8ff 75 uint32_t value = dac_read(obj);
bogdanm 0:9b334a45a8ff 76 return (float)value * (1.0f / (float)RANGE_12BIT);
bogdanm 0:9b334a45a8ff 77 }
bogdanm 0:9b334a45a8ff 78
bogdanm 0:9b334a45a8ff 79 uint16_t analogout_read_u16(dac_t *obj) {
bogdanm 0:9b334a45a8ff 80 uint32_t value = dac_read(obj); // 12-bit
bogdanm 0:9b334a45a8ff 81 return (value << 4) | ((value >> 8) & 0x003F);
bogdanm 0:9b334a45a8ff 82 }
bogdanm 0:9b334a45a8ff 83
bogdanm 0:9b334a45a8ff 84 #endif