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_KLXX/analogin_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 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "analogin_api.h"
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 20 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 21 #include "clk_freqs.h"
<> 144:ef7eb2e8f9f7 22 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 23
<> 144:ef7eb2e8f9f7 24 #define MAX_FADC 6000000
<> 144:ef7eb2e8f9f7 25 #define CHANNELS_A_SHIFT 5
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27
<> 144:ef7eb2e8f9f7 28 void analogin_init(analogin_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 29 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
<> 144:ef7eb2e8f9f7 30 MBED_ASSERT(obj->adc != (ADCName)NC);
<> 144:ef7eb2e8f9f7 31
<> 144:ef7eb2e8f9f7 32 SIM->SCGC6 |= SIM_SCGC6_ADC0_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 uint32_t cfg2_muxsel = ADC_CFG2_MUXSEL_MASK;
<> 144:ef7eb2e8f9f7 38 if (obj->adc & (1 << CHANNELS_A_SHIFT)) {
<> 144:ef7eb2e8f9f7 39 cfg2_muxsel = 0;
<> 144:ef7eb2e8f9f7 40 }
<> 144:ef7eb2e8f9f7 41
<> 144:ef7eb2e8f9f7 42 // bus clk
<> 144:ef7eb2e8f9f7 43 uint32_t PCLK = bus_frequency();
<> 144:ef7eb2e8f9f7 44 uint32_t clkdiv;
<> 144:ef7eb2e8f9f7 45 for (clkdiv = 0; clkdiv < 4; clkdiv++) {
<> 144:ef7eb2e8f9f7 46 if ((PCLK >> clkdiv) <= MAX_FADC)
<> 144:ef7eb2e8f9f7 47 break;
<> 144:ef7eb2e8f9f7 48 }
<> 144:ef7eb2e8f9f7 49 if (clkdiv == 4) //Set max div
<> 144:ef7eb2e8f9f7 50 clkdiv = 0x7;
<> 144:ef7eb2e8f9f7 51
<> 144:ef7eb2e8f9f7 52 ADC0->SC1[1] = ADC_SC1_ADCH(obj->adc & ~(1 << CHANNELS_A_SHIFT));
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 ADC0->CFG1 = ADC_CFG1_ADLPC_MASK // Low-Power Configuration
<> 144:ef7eb2e8f9f7 55 | ADC_CFG1_ADIV(clkdiv & 0x3) // Clock Divide Select: (Input Clock)/8
<> 144:ef7eb2e8f9f7 56 | ADC_CFG1_ADLSMP_MASK // Long Sample Time
<> 144:ef7eb2e8f9f7 57 | ADC_CFG1_MODE(3) // (16)bits Resolution
<> 144:ef7eb2e8f9f7 58 | ADC_CFG1_ADICLK(clkdiv >> 2); // Input Clock: (Bus Clock)/2
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 ADC0->CFG2 = cfg2_muxsel // ADxxb or ADxxa channels
<> 144:ef7eb2e8f9f7 61 | ADC_CFG2_ADHSC_MASK // High-Speed Configuration
<> 144:ef7eb2e8f9f7 62 | ADC_CFG2_ADLSTS(0); // Long Sample Time Select
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 ADC0->SC2 = ADC_SC2_REFSEL(0); // Default Voltage Reference
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 ADC0->SC3 = ADC_SC3_AVGE_MASK // Hardware Average Enable
<> 144:ef7eb2e8f9f7 67 | ADC_SC3_AVGS(0); // 4 Samples Averaged
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 pinmap_pinout(pin, PinMap_ADC);
<> 144:ef7eb2e8f9f7 70 }
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 uint16_t analogin_read_u16(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 73 // start conversion
<> 144:ef7eb2e8f9f7 74 ADC0->SC1[0] = ADC_SC1_ADCH(obj->adc & ~(1 << CHANNELS_A_SHIFT));
<> 144:ef7eb2e8f9f7 75
<> 144:ef7eb2e8f9f7 76 // Wait Conversion Complete
<> 144:ef7eb2e8f9f7 77 while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK);
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 // Return value
<> 144:ef7eb2e8f9f7 80 return (uint16_t)ADC0->R[0];
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 float analogin_read(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 84 uint16_t value = analogin_read_u16(obj);
<> 144:ef7eb2e8f9f7 85 return (float)value * (1.0f / (float)0xFFFF);
<> 144:ef7eb2e8f9f7 86 }
<> 144:ef7eb2e8f9f7 87