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Fork of FastAnalogIn by
FastAnalogIn_LPC11UXX.cpp
- Committer:
- Sissors
- Date:
- 2014-06-28
- Revision:
- 8:68082fdde730
File content as of revision 8:68082fdde730:
#ifdef TARGET_LPC11UXX
#include "FastAnalogIn.h"
static inline int div_round_up(int x, int y)
{
return (x + (y - 1)) / y;
}
#define LPC_IOCON0_BASE (LPC_IOCON_BASE)
#define LPC_IOCON1_BASE (LPC_IOCON_BASE + 0x60)
#define MAX_ADC_CLK 4500000
static const PinMap PinMap_ADC[] = {
{P0_11, ADC0_0, 0x02},
{P0_12, ADC0_1, 0x02},
{P0_13, ADC0_2, 0x02},
{P0_14, ADC0_3, 0x02},
{P0_15, ADC0_4, 0x02},
{P0_16, ADC0_5, 0x01},
{P0_22, ADC0_6, 0x01},
{P0_23, ADC0_7, 0x01},
{NC , NC , 0 }
};
static int channel_usage[8] = {0,0,0,0,0,0,0,0};
FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
{
ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
if (ADCnumber == (uint32_t)NC)
error("ADC pin mapping failed");
datareg = (uint32_t*) (&LPC_ADC->DR0 + ADCnumber);
// Power up ADC
LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
uint32_t pin_number = (uint32_t)pin;
__IO uint32_t *reg = (pin_number < 32) ? (__IO uint32_t*)(LPC_IOCON0_BASE + 4 * pin_number) : (__IO uint32_t*)(LPC_IOCON1_BASE + 4 * (pin_number - 32));
// set pin to ADC mode
*reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
uint32_t clkdiv = div_round_up(SystemCoreClock, MAX_ADC_CLK) - 1;
LPC_ADC->CR = (0 << 0) // no channels selected
| (clkdiv << 8) // max of 4.5MHz
| (1 << 16) // BURST = 1, hardware controlled
| ( 0 << 17 ); // CLKS = 0, we stick to 10 bit mode
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
channel_usage[ADCnumber]++;
LPC_ADC->CR |= (1<<ADCnumber);
running = true;
} else
disable();
}
}
void FastAnalogIn::disable( void )
{
//If currently running
if (running) {
channel_usage[ADCnumber]--;
if (channel_usage[ADCnumber]==0)
LPC_ADC->CR &= ~(1<<ADCnumber);
}
running = false;
}
unsigned short FastAnalogIn::read_u16( void )
{
unsigned int retval;
//If object is enabled return current value of datareg
if (running)
retval = *datareg;
//If it isn't running, enable it and wait until new value is written to datareg
else {
//Force a read to clear done bit, enable the ADC channel
retval = *datareg;
enable();
//Wait until it is converted
while(1) {
retval = *datareg;
if ((retval>>31) == 1)
break;
}
//Disable again
disable();
}
//Do same thing as standard mbed lib, unused bit 0-3, replicate 4-7 in it
retval &= ~0xFFFF003F;
retval |= (retval >> 6) & 0x003F;
return retval;
}
#endif //defined TARGET_LPC11UXX
