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bx-adc.cpp
- Committer:
- backman
- Date:
- 2014-06-03
- Revision:
- 1:82bc25a7b68b
File content as of revision 1:82bc25a7b68b:
#include "bx-adc.h" #include "clk_freqs.h" #define MAX_FADC 6000000 #define CHANNELS_A_SHIFT 5 FastAnalogIn::FastAnalogIn(PinName pin, bool enabled) { ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC); if (ADCnumber == (ADCName)NC) { error("ADC pin mapping failed"); } SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK; //----------------------------------------------------- uint32_t port = (uint32_t)pin >> PORT_SHIFT; SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port); uint32_t cfg2_muxsel = ADC_CFG2_MUXSEL_MASK; if (ADCnumber & (1 << CHANNELS_A_SHIFT)) { cfg2_muxsel = 0; } //------------------------------------------------------ // bus clk uint32_t PCLK = bus_frequency(); uint32_t clkdiv; for (clkdiv = 0; clkdiv < 4; clkdiv++) { if ((PCLK >> clkdiv) <= MAX_FADC) break; } if (clkdiv == 4) //Set max div clkdiv = 0x7; ADC0->SC1[1] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); ADC0->CFG1 = ADC_CFG1_ADIV(clkdiv & 0x3) // Clock Divide Select: (Input Clock)/8 | ADC_CFG1_MODE(3) // (16)bits Resolution | ADC_CFG1_ADICLK(clkdiv >> 2); // Input Clock: (Bus Clock)/2 ADC0->CFG2 = cfg2_muxsel // ADxxb or ADxxa channels | ADC_CFG2_ADACKEN_MASK // Asynchronous Clock Output Enable | ADC_CFG2_ADHSC_MASK; // High-Speed Configuration ADC0->SC2 = ADC_SC2_REFSEL(0); // Default Voltage Reference pinmap_pinout(pin, PinMap_ADC); //Enable channel running = false; enable(enabled); } void FastAnalogIn::enable(bool enabled) { //If currently not running if (!running) { if (enabled) { //Enable the ADC channel ADC0->SC3 |= ADC_SC3_ADCO_MASK; // Enable continuous conversion ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); //Start conversion running = true; } else disable(); } } void FastAnalogIn::disable( void ) { //If currently running if (running) { ADC0->SC3 &= ~ADC_SC3_ADCO_MASK; // Disable continuous conversion } running = false; } uint16_t FastAnalogIn::read_u16() { if (!running) { // start conversion ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); // Wait Conversion Complete while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK); } if(running && ((ADC0->SC1[0]&ADC_SC1_ADCH_MASK) != (ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT))))) { running = false; enable(); while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK); } // Return value return (uint16_t)ADC0->R[0]; }