# B-G474E-DPOW1 DCDC Code Map

## Runtime knobs

The live configuration object is:

```c
g_dcdc_config
```

Edit it in Keil **Watch** while the target is running.

Useful fields:

```c
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:

```c
0 = DCDC_MODE_MONITOR
1 = DCDC_MODE_PWM_TEST
2 = DCDC_MODE_CLOSED_LOOP
```

## Startup path

`main.c`:

1. `Board_Init()` starts clocks, SysTick, GPIO basics.
2. `Retarget_Init()` enables `printf()` through `USART3`.
3. `DCDC_Init()` prepares ADC and HRTIM Timer C.
4. `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:

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

Dead-time is enabled by:

```c
timer->OUTxR |= HRTIM_OUTR_DTEN;
```

## ADC path

`DCDC_ReadMeasurements()` reads:

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

Raw ADC values are converted through:

```c
adc_raw_to_mv()
sense_mv_to_voltage_mv()
sense_mv_to_current_ma()
```

## Safety path

The closed-loop mode checks:

```c
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

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