36.5.15 Programmable Slew Rate
Each output can be configured for slew rate control. Slew rate control can be enabled by setting the bit SR of the PIO_CFGRx if the corresponding line is Non-Secure, or S_PIO_CFGRx if the I/O line is Secure. For details, refer to the section “Electrical Characteristics”.
Slew rate control does not apply to high-speed I/O lines.