first level of reset: the application software must either: a) partially reset the peripheral, by a write and clear of the enable bit of the I3C configuration register (write EN = 0). This resets the I3C bus interface and the I3C kernel sub-parts, without modifying the content of the I3C APB registers (except the EN bit). b) fully reset the peripheral, including all its registers, via a write and set of the I3C reset control bit of the RCC (reset and clock controller) register.
second level of reset: the application software must issue a warm reset, also known as a system reset. This (see Section 11: Reset and clock control (RCC)) has the same impact as a pin reset (NRST = 0): – the software writes and sets the SYSRESETREQ control bit of the AITR register, when the device is controlled by a Cortex®-M. – the software writes and sets SYSRST = 1 in the RCC_GRSTCSETR register, when the device is controlled by a Cortex®-A.