embedded-peripheral-bringup

# Embedded Peripheral Bring-Up ## Overview Use this skill to bring up peripherals from the outside in: board wiring, pin mux, clocks, reset state, electrical mode, driver configuration, interrupts/DMA, and observable signals. Avoid rewriting drivers before proving the peripheral can physically signal. ## When To Use Use this skill when: - GPIO, UART, SPI, I2C, PWM, ADC, timer, DMA, or interrupt behavior is wrong. - A peripheral has no signal, wrong timing, stuck bus, bad data, or only works sometimes. - The user has schematic snippets, pin mappings, logic analyzer traces, oscilloscope captures, or register dumps. Do not use this skill when the chip is not booting or the firmware cannot be flashed; resolve those first. ## First Questions Ask for: - MCU/SoC and board. - Peripheral and exact pins. - Expected behavior versus observed behavior. - Clock frequency and driver/framework. - Schematic/pinout evidence and whether signals were measured. - Whether interrupts, DMA, or low-power modes are involved. ## Workflow 1. Prove the board path. Confirm the signal pin, package pin, board net, connector, level shifter, pull-up/down, and external device. 1. Prove pin configuration. Check mux/alternate function, electrical mode, drive strength, pull, analog/digital mode, and open-drain requirements. 1. Prove clock and reset. Confirm peripheral bus clock, module reset release, prescaler, and any power domain enable. 1. Start with the simplest observable action. To...