david dicarlo / mbed-src-FLL48

mbed library sources: Modified to operate FRDM-KL25Z at 48MHz from internal 32kHz oscillator (nothing else changed).

Fork of mbed-src by mbed official

The only file that changed is: mbed-src-FLL48/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.h

targets/hal/TARGET_NXP/TARGET_LPC11CXX/analogin_api.c@20:4263a77256ae, 2013-09-10 (annotated)

Committer:
bogdanm
Date:
Tue Sep 10 15:14:19 2013 +0300
Revision:
20:4263a77256ae
Sync with git revision 171dda705c947bf910926a0b73d6a4797802554d

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 */
bogdanm 20:4263a77256ae 16 #include "analogin_api.h"
bogdanm 20:4263a77256ae 17 #include "cmsis.h"
bogdanm 20:4263a77256ae 18 #include "pinmap.h"
bogdanm 20:4263a77256ae 19 #include "error.h"
bogdanm 20:4263a77256ae 20
bogdanm 20:4263a77256ae 21 #define ANALOGIN_MEDIAN_FILTER 1
bogdanm 20:4263a77256ae 22
bogdanm 20:4263a77256ae 23 #define ADC_10BIT_RANGE 0x3FF
bogdanm 20:4263a77256ae 24 #define ADC_12BIT_RANGE 0xFFF
bogdanm 20:4263a77256ae 25
bogdanm 20:4263a77256ae 26 static inline int div_round_up(int x, int y) {
bogdanm 20:4263a77256ae 27 return (x + (y - 1)) / y;
bogdanm 20:4263a77256ae 28 }
bogdanm 20:4263a77256ae 29
bogdanm 20:4263a77256ae 30 static const PinMap PinMap_ADC[] = {
bogdanm 20:4263a77256ae 31 {P0_11, ADC0_0, 2},
bogdanm 20:4263a77256ae 32 {P1_0 , ADC0_1, 2},
bogdanm 20:4263a77256ae 33 {P1_1 , ADC0_2, 2},
bogdanm 20:4263a77256ae 34 {P1_2 , ADC0_3, 2},
bogdanm 20:4263a77256ae 35 {P1_3 , ADC0_4, 2},
bogdanm 20:4263a77256ae 36 {P1_4 , ADC0_5, 1},
bogdanm 20:4263a77256ae 37 {P1_10, ADC0_6, 1},
bogdanm 20:4263a77256ae 38 {P1_11, ADC0_7, 1},
bogdanm 20:4263a77256ae 39 {NC , NC , 0}
bogdanm 20:4263a77256ae 40 };
bogdanm 20:4263a77256ae 41
bogdanm 20:4263a77256ae 42 #define ADC_RANGE ADC_10BIT_RANGE
bogdanm 20:4263a77256ae 43
bogdanm 20:4263a77256ae 44 void analogin_init(analogin_t *obj, PinName pin) {
bogdanm 20:4263a77256ae 45 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
bogdanm 20:4263a77256ae 46 if (obj->adc == (uint32_t)NC) {
bogdanm 20:4263a77256ae 47 error("ADC pin mapping failed");
bogdanm 20:4263a77256ae 48 }
bogdanm 20:4263a77256ae 49
bogdanm 20:4263a77256ae 50 // Power up ADC
bogdanm 20:4263a77256ae 51 LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
bogdanm 20:4263a77256ae 52 LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
bogdanm 20:4263a77256ae 53
bogdanm 20:4263a77256ae 54 uint32_t offset = (uint32_t)pin & 0xff;
bogdanm 20:4263a77256ae 55 __IO uint32_t *reg = (__IO uint32_t*)(LPC_IOCON_BASE + offset);
bogdanm 20:4263a77256ae 56
bogdanm 20:4263a77256ae 57 // set pin to ADC mode
bogdanm 20:4263a77256ae 58 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
bogdanm 20:4263a77256ae 59
bogdanm 20:4263a77256ae 60 uint32_t PCLK = SystemCoreClock;
bogdanm 20:4263a77256ae 61 uint32_t MAX_ADC_CLK = 4500000;
bogdanm 20:4263a77256ae 62 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
bogdanm 20:4263a77256ae 63
bogdanm 20:4263a77256ae 64 LPC_ADC->CR = (0 << 0) // no channels selected
bogdanm 20:4263a77256ae 65 | (clkdiv << 8) // max of 4.5MHz
bogdanm 20:4263a77256ae 66 | (0 << 16) // BURST = 0, software controlled
bogdanm 20:4263a77256ae 67 | ( 0 << 17 ); // CLKS = 0, not applicable
bogdanm 20:4263a77256ae 68
bogdanm 20:4263a77256ae 69 pinmap_pinout(pin, PinMap_ADC);
bogdanm 20:4263a77256ae 70 }
bogdanm 20:4263a77256ae 71
bogdanm 20:4263a77256ae 72 static inline uint32_t adc_read(analogin_t *obj) {
bogdanm 20:4263a77256ae 73 // Select the appropriate channel and start conversion
bogdanm 20:4263a77256ae 74 LPC_ADC->CR &= ~0xFF;
bogdanm 20:4263a77256ae 75 LPC_ADC->CR |= 1 << (int)obj->adc;
bogdanm 20:4263a77256ae 76 LPC_ADC->CR |= 1 << 24;
bogdanm 20:4263a77256ae 77
bogdanm 20:4263a77256ae 78 // Repeatedly get the sample data until DONE bit
bogdanm 20:4263a77256ae 79 unsigned int data;
bogdanm 20:4263a77256ae 80 do {
bogdanm 20:4263a77256ae 81 data = LPC_ADC->GDR;
bogdanm 20:4263a77256ae 82 } while ((data & ((unsigned int)1 << 31)) == 0);
bogdanm 20:4263a77256ae 83
bogdanm 20:4263a77256ae 84 // Stop conversion
bogdanm 20:4263a77256ae 85 LPC_ADC->CR &= ~(1 << 24);
bogdanm 20:4263a77256ae 86
bogdanm 20:4263a77256ae 87 return (data >> 6) & ADC_RANGE; // 10 bit
bogdanm 20:4263a77256ae 88 }
bogdanm 20:4263a77256ae 89
bogdanm 20:4263a77256ae 90 static inline void order(uint32_t *a, uint32_t *b) {
bogdanm 20:4263a77256ae 91 if (*a > *b) {
bogdanm 20:4263a77256ae 92 uint32_t t = *a;
bogdanm 20:4263a77256ae 93 *a = *b;
bogdanm 20:4263a77256ae 94 *b = t;
bogdanm 20:4263a77256ae 95 }
bogdanm 20:4263a77256ae 96 }
bogdanm 20:4263a77256ae 97
bogdanm 20:4263a77256ae 98 static inline uint32_t adc_read_u32(analogin_t *obj) {
bogdanm 20:4263a77256ae 99 uint32_t value;
bogdanm 20:4263a77256ae 100 #if ANALOGIN_MEDIAN_FILTER
bogdanm 20:4263a77256ae 101 uint32_t v1 = adc_read(obj);
bogdanm 20:4263a77256ae 102 uint32_t v2 = adc_read(obj);
bogdanm 20:4263a77256ae 103 uint32_t v3 = adc_read(obj);
bogdanm 20:4263a77256ae 104 order(&v1, &v2);
bogdanm 20:4263a77256ae 105 order(&v2, &v3);
bogdanm 20:4263a77256ae 106 order(&v1, &v2);
bogdanm 20:4263a77256ae 107 value = v2;
bogdanm 20:4263a77256ae 108 #else
bogdanm 20:4263a77256ae 109 value = adc_read(obj);
bogdanm 20:4263a77256ae 110 #endif
bogdanm 20:4263a77256ae 111 return value;
bogdanm 20:4263a77256ae 112 }
bogdanm 20:4263a77256ae 113
bogdanm 20:4263a77256ae 114 uint16_t analogin_read_u16(analogin_t *obj) {
bogdanm 20:4263a77256ae 115 uint32_t value = adc_read_u32(obj);
bogdanm 20:4263a77256ae 116
bogdanm 20:4263a77256ae 117 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
bogdanm 20:4263a77256ae 118 }
bogdanm 20:4263a77256ae 119
bogdanm 20:4263a77256ae 120 float analogin_read(analogin_t *obj) {
bogdanm 20:4263a77256ae 121 uint32_t value = adc_read_u32(obj);
bogdanm 20:4263a77256ae 122 return (float)value * (1.0f / (float)ADC_RANGE);
bogdanm 20:4263a77256ae 123 }