FlexPWM

A TFT backlight can be dimmed by an MCU timer or by the display controller’s own PWM, set with the MIPI DCS brightness commands. What each option costs, what it frees up, and the traps when you move from one to the other.

GPIO, ADC and FlexPWM interrupts follow one NVIC pattern but differ in where the trigger lives and how the flag clears. Plus the audit that matters with FreeRTOS: which ISRs sit above the syscall barrier, and therefore must never touch a FreeRTOS API.