B-G474E-DPOW1 DCDC Code Map

Runtime knobs

The live configuration object is:

g_dcdc_config

Edit it in Keil Watch while the target is running.

Useful fields:

g_dcdc_config.mode
g_dcdc_config.pwm.frequency_hz
g_dcdc_config.pwm.test_duty_permille
g_dcdc_config.pwm.deadtime_enable
g_dcdc_config.pwm.deadtime_rising_ticks
g_dcdc_config.pwm.deadtime_falling_ticks
g_dcdc_config.limits.target_vout_mv
g_dcdc_config.limits.current_limit_ma

Modes:

0 = DCDC_MODE_MONITOR
1 = DCDC_MODE_PWM_TEST
2 = DCDC_MODE_CLOSED_LOOP

Startup path

main.c:

Board_Init() starts clocks, SysTick, GPIO basics.
Retarget_Init() enables printf() through USART3.
DCDC_Init() prepares ADC and HRTIM Timer C.
DCDC_Service1ms() runs every 1 ms and applies live runtime edits.

HRTIM PWM path

dcdc.c:

hrtim1_timer_c_init() configures HRTIM1 Timer C.
DCDC_StartPwmTest() starts open-loop analyzer PWM.
hrtim1_apply_pwm_config() applies live frequency and dead-time edits.
hrtim1_set_duty() updates CMP1, which sets the PB12/PB13 split point.

Current complementary test routing:

PB12 / CHC1: set at period, reset at CMP1
PB13 / CHC2: set at CMP1, reset at period

Dead-time is enabled by:

timer->OUTxR |= HRTIM_OUTR_DTEN;

ADC path

DCDC_ReadMeasurements() reads:

PA1 / ADC1_IN2 = VIN
PA2 / ADC1_IN3 = input current average
PA3 / ADC1_IN4 = VOUT

Raw ADC values are converted through:

adc_raw_to_mv()
sense_mv_to_voltage_mv()
sense_mv_to_current_ma()

Safety path

The closed-loop mode checks:

g_dcdc_config.limits.min_vin_mv
g_dcdc_config.limits.max_vout_mv
g_dcdc_config.limits.hard_current_ma

If a limit trips, latch_fault() disables HRTIM outputs, clears duty, opens the USB-PD/VIN switch, and moves the state to DCDC_STATE_FAULT.

Current safe workflow

Keep g_dcdc_config.mode = 1.
Tune g_dcdc_config.pwm.deadtime_*_ticks.
Verify PB12/PB13 on the logic analyzer.
Only after clean waveforms, move toward closed-loop testing.

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