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Fixed adc_init() function.

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See #1418
This commit is contained in:
Cristian Maglie
2013-10-09 15:54:47 +02:00
parent d1d561ddb7
commit 40dce96f11
5 changed files with 87 additions and 36 deletions
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51
hardware/arduino/sam/system/libsam/source/adc.c
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@@ -46,7 +46,7 @@ extern "C" {
* @{
*/
#if SAM3S_SERIES || SAM4S_SERIES || SAM3N_SERIES || SAM3XA_SERIES
#if SAM3S_SERIES || SAM4S_SERIES || SAM3N_SERIES
/**
* \brief Initialize the given ADC with the specified ADC clock and startup time.
*
@@ -80,6 +80,55 @@ uint32_t adc_init(Adc *p_adc, const uint32_t ul_mck,
ADC_MR_STARTUP_Msk);
return 0;
}
#elif SAM3XA_SERIES
/**
* \brief Initialize the given ADC with the specified ADC clock and startup time.
*
* \param p_adc Pointer to an ADC instance.
* \param ul_mck Main clock of the device (value in Hz).
* \param ul_adc_clock Analog-to-Digital conversion clock (value in Hz).
* \param uc_startup ADC start up time. Please refer to the product datasheet
* for details.
*
* \return 0 on success.
*/
uint32_t adc_init(Adc *p_adc, const uint32_t ul_mck,
const uint32_t ul_adc_clock, const uint8_t uc_startuptime)
{
uint32_t startup_table[] = { 0, 8, 16, 24, 64, 80, 96, 112, 512, 576, 640, 704, 768, 832, 896, 960 };
uint32_t ul_prescal, ul_startup, ul_mr_startup, ul_real_adc_clock;
p_adc->ADC_CR = ADC_CR_SWRST;
/* Reset Mode Register. */
p_adc->ADC_MR = 0;
/* Reset PDC transfer. */
p_adc->ADC_PTCR = (ADC_PTCR_RXTDIS | ADC_PTCR_TXTDIS);
p_adc->ADC_RCR = 0;
p_adc->ADC_RNCR = 0;
if (ul_mck % (2 * ul_adc_clock)) {
// Division with reminder
ul_prescal = ul_mck / (2 * ul_adc_clock);
} else {
// Whole division
ul_prescal = ul_mck / (2 * ul_adc_clock) - 1;
}
ul_real_adc_clock = ul_mck / (2 * (ul_prescal + 1));
// ADC clocks needed to get ul_startuptime uS
ul_startup = (ul_real_adc_clock / 1000000) * uc_startuptime;
// Find correct MR_STARTUP value from conversion table
for (ul_mr_startup=0; ul_mr_startup<16; ul_mr_startup++) {
if (startup_table[ul_mr_startup] >= ul_startup)
break;
}
if (ul_mr_startup==16)
return -1;
p_adc->ADC_MR |= ADC_MR_PRESCAL(ul_prescal) |
((ul_mr_startup << ADC_MR_STARTUP_Pos) & ADC_MR_STARTUP_Msk);
return 0;
}
#elif SAM3U_SERIES
/**
* \brief Initialize the given ADC with the specified ADC clock and startup time.