blink Directory Reference

Directory dependency graph for blink:

Directories
	src

Detailed Description

Toggles user LED1 (P600, blue) at a clean 1 Hz off SysTick, with no busy-wait.

This is the smallest surface in the tree that can fail, which is the whole point: it is the first thing to run on a new board or after a boot change, because if blink is dark then nothing further up the stack is worth debugging.

It deliberately does not bring the CGC up. It runs at the reset-default MOCO rate – about 8.4 MHz, measured on DWT.CYCCNT and consistent with the RA-family nominal 8 MHz – and k_blink_cpu_hz_at_reset in src/main.c encodes that. Cache, MPU and TrustZone bring-up are left out for the same reason. clock_check is the app that takes the chip up to its rated CPUCLK0; blink_hal is the same blink driven through the HAL instead.

The stack lives in the first on-chip SRAM bank only; the second bank needs its own MSTPCR and SRAMSAR programming before anything can be placed there.

LED1 / P600 wiring follows EK-RA8D2 v1 UM (R20UT5523EG0101) Table 24 "EK-RA8D2 Board LED Functions" p 31.