64.5.4.1 PIO Backup Controller

The SECUMOD includes a local programmable IO controller powered by VDDBU which handles the eight PIOBU I/O pins.

Each I/O line is controlled by the IO controller and each pin can be configured to be driven. This is done by writing in the corresponding IO Backup register (SECUMOD_PIOBUx). When SECUMOD_PIOBUx.OUTPUT is at ‘0’, the corresponding I/O line is used as an input only. When this bit is at ‘1’, the corresponding I/O line is driven by the backup IO controller.