FastAnalogIn_KLXX_K20D50M.cpp

00001 #if defined(TARGET_KLXX) || defined(TARGET_K20D50M)
00002 
00003 #include "FastAnalogIn.h"
00004 #include "clk_freqs.h"
00005 
00006 #define MAX_FADC            6000000
00007 #define CHANNELS_A_SHIFT    5
00008 
00009 #ifdef TARGET_K20D50M
00010 static const PinMap PinMap_ADC[] = {
00011     {PTC2, ADC0_SE4b, 0},
00012     {PTD1, ADC0_SE5b, 0},
00013     {PTD5, ADC0_SE6b, 0},
00014     {PTD6, ADC0_SE7b, 0},
00015     {PTB0, ADC0_SE8,  0},
00016     {PTB1, ADC0_SE9,  0},
00017     {PTB2, ADC0_SE12, 0},
00018     {PTB3, ADC0_SE13, 0},
00019     {PTC0, ADC0_SE14, 0},
00020     {PTC1, ADC0_SE15, 0},
00021     {NC,   NC,        0}
00022 };
00023 #endif
00024 
00025 FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
00026 {
00027     if (pin == NC)
00028         return;
00029     
00030     ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
00031     if (ADCnumber == (ADCName)NC) {
00032         error("ADC pin mapping failed");
00033     }
00034 
00035     SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK;
00036 
00037     uint32_t port = (uint32_t)pin >> PORT_SHIFT;
00038     SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
00039 
00040     uint32_t cfg2_muxsel = ADC_CFG2_MUXSEL_MASK;
00041     if (ADCnumber & (1 << CHANNELS_A_SHIFT)) {
00042         cfg2_muxsel = 0;
00043     }
00044     
00045     // bus clk
00046     uint32_t PCLK = bus_frequency();
00047     uint32_t clkdiv;
00048     for (clkdiv = 0; clkdiv < 4; clkdiv++) {
00049         if ((PCLK >> clkdiv) <= MAX_FADC)
00050             break;
00051     }
00052     if (clkdiv == 4)                    //Set max div
00053         clkdiv = 0x7;
00054 
00055     ADC0->SC1[1] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
00056 
00057     ADC0->CFG1 = ADC_CFG1_ADIV(clkdiv & 0x3)    // Clock Divide Select: (Input Clock)/8
00058                | ADC_CFG1_MODE(3)               // (16)bits Resolution
00059                | ADC_CFG1_ADICLK(clkdiv >> 2);  // Input Clock: (Bus Clock)/2
00060 
00061     ADC0->CFG2 = cfg2_muxsel            // ADxxb or ADxxa channels
00062                | ADC_CFG2_ADACKEN_MASK  // Asynchronous Clock Output Enable
00063                | ADC_CFG2_ADHSC_MASK;   // High-Speed Configuration
00064 
00065     ADC0->SC2 = ADC_SC2_REFSEL(0);      // Default Voltage Reference
00066 
00067     pinmap_pinout(pin, PinMap_ADC);
00068 
00069     //Enable channel
00070     running = false;
00071     enable(enabled);
00072 }
00073 
00074 void FastAnalogIn::enable(bool enabled)
00075 {
00076     //If currently not running
00077     if (!running) {
00078         if (enabled) {
00079             //Enable the ADC channel
00080             ADC0->SC3 |= ADC_SC3_ADCO_MASK;       // Enable continuous conversion
00081             ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));  //Start conversion
00082             running = true;
00083         } else
00084             disable();
00085     }
00086 }
00087  
00088 void FastAnalogIn::disable( void )
00089 {
00090     //If currently running
00091     if (running) {
00092         ADC0->SC3 &= ~ADC_SC3_ADCO_MASK;      // Disable continuous conversion
00093     }
00094     running = false;
00095 }
00096 
00097 uint16_t FastAnalogIn::read_u16()
00098 {
00099     if (!running)
00100     {
00101         // start conversion
00102         ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
00103         // Wait Conversion Complete
00104         while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK);
00105     }
00106     if(running && ((ADC0->SC1[0]&ADC_SC1_ADCH_MASK) != (ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)))))
00107     {
00108         running = false;
00109         enable();
00110         while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK);
00111     }
00112     // Return value
00113     return (uint16_t)ADC0->R[0];
00114 }
00115 
00116 #endif //defined TARGET_KLXX
00117