esp-idf/components/soc/esp32/test/test_rtc_clk.c
Ivan Grokhotkov 3323f31cfb soc: implement XTAL frequency detection
ROM code already implements XTAL frequency detection, but it uses the 8M
clock before the clock tuning parameters are initialized. With the
zero clock tuning parameter, 8M clock has significant frequency deviation
at high temperatures, which can lead to erroneous detection of 40 MHz
crystal as a 26 MHz one.

This change adds XTAL frequency detection code to rtc_clk_init routine,
and detection is performed after the 8M clock tuning parameter as been
initialized.
2017-04-24 15:29:30 +08:00

92 lines
2.6 KiB
C

#include <stdio.h>
#include "unity.h"
#include "rom/ets_sys.h"
#include "soc/rtc.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/rtc_io_reg.h"
#include "soc/sens_reg.h"
#include "soc/io_mux_reg.h"
#include "driver/rtc_io.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#define CALIBRATE_ONE(cali_clk) calibrate_one(cali_clk, #cali_clk)
static uint32_t calibrate_one(rtc_cal_sel_t cal_clk, const char* name)
{
const uint32_t cal_count = 1000;
const float factor = (1 << 19) * 1000.0f;
uint32_t cali_val;
printf("%s:\n", name);
for (int i = 0; i < 5; ++i) {
printf("calibrate (%d): ", i);
cali_val = rtc_clk_cal(cal_clk, cal_count);
printf("%.3f kHz\n", factor / (float) cali_val);
}
return cali_val;
}
TEST_CASE("RTC_SLOW_CLK sources calibration", "[rtc_clk]")
{
rtc_clk_32k_enable(true);
rtc_clk_8m_enable(true, true);
CALIBRATE_ONE(RTC_CAL_RTC_MUX);
CALIBRATE_ONE(RTC_CAL_8MD256);
uint32_t cal_32k = CALIBRATE_ONE(RTC_CAL_32K_XTAL);
if (cal_32k == 0) {
printf("32K XTAL OSC has not started up");
} else {
printf("switching to RTC_SLOW_FREQ_32K_XTAL: ");
rtc_clk_slow_freq_set(RTC_SLOW_FREQ_32K_XTAL);
printf("done\n");
CALIBRATE_ONE(RTC_CAL_RTC_MUX);
CALIBRATE_ONE(RTC_CAL_8MD256);
CALIBRATE_ONE(RTC_CAL_32K_XTAL);
}
printf("switching to RTC_SLOW_FREQ_8MD256: ");
rtc_clk_slow_freq_set(RTC_SLOW_FREQ_8MD256);
printf("done\n");
CALIBRATE_ONE(RTC_CAL_RTC_MUX);
CALIBRATE_ONE(RTC_CAL_8MD256);
CALIBRATE_ONE(RTC_CAL_32K_XTAL);
}
/* The following two are not unit tests, but are added here to make it easy to
* check the frequency of 150k/32k oscillators. The following two "tests" will
* output either 32k or 150k clock to GPIO25.
*/
static void pull_out_clk(int sel)
{
REG_SET_BIT(RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_MUX_SEL_M);
REG_CLR_BIT(RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_RDE_M | RTC_IO_PDAC1_RUE_M);
REG_SET_FIELD(RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_FUN_SEL, 1);
REG_SET_FIELD(SENS_SAR_DAC_CTRL1_REG, SENS_DEBUG_BIT_SEL, 0);
REG_SET_FIELD(RTC_IO_RTC_DEBUG_SEL_REG, RTC_IO_DEBUG_SEL0, sel);
}
TEST_CASE("Output 150k clock to GPIO25", "[rtc_clk][ignore]")
{
pull_out_clk(RTC_IO_DEBUG_SEL0_150K_OSC);
}
TEST_CASE("Output 32k XTAL clock to GPIO25", "[rtc_clk][ignore]")
{
rtc_clk_32k_enable(true);
pull_out_clk(RTC_IO_DEBUG_SEL0_32K_XTAL);
}
TEST_CASE("Output 8M XTAL clock to GPIO25", "[rtc_clk][ignore]")
{
rtc_clk_8m_enable(true, true);
SET_PERI_REG_MASK(RTC_IO_RTC_DEBUG_SEL_REG, RTC_IO_DEBUG_12M_NO_GATING);
pull_out_clk(RTC_IO_DEBUG_SEL0_8M);
}