ARM, RISC-V контроллеры

Ответ: "This boot loader is located in the upper 8 kB of flash memory... The flash boot loader code is execute every time the part is powered on or reset. The loader can execute the ISP command handler or pass execution to the user application code. A LOW level, after reset, at the P0.14 pin is considered as the external hardware request to start the ISP command handler. The boot loader samples this pin during reset..." Assuming that proper signal is present on X1 pin when the rising edge on RST pin is generated, it may take up to 3 ms before P0.14 is sampled and the decision on whether to continue with user code or ISP handler is made.