SPRUJ79 November 2024 F29H850TU
The power-on reset (POR) circuit creates a clean reset throughout the device during power-up, suppressing glitches on the GPIOs. The XRS pin is held low for the duration of the POR. In most applications, XRS is held low long enough to reset other system ICs, but some applications can require a longer pulse. In these cases, XRS can be driven low externally to provide the correct reset duration. A POR resets everything that XRS does, along with the register – the reset cause register (RESC).
After a POR, the POR and XRSn bits in RESC are set. These bits are then cleared by the boot ROM.