Контроллер портов ввода-вывода (GPIO): список регистров

  Unused

  PG_DAT

If the port is configured as input, the corresponding bit is the pin state.
If the port is configured as output, the pin state is the same as the corresponding bit.
he read bit value is the value setup by software.
If the port is configured as functional pin, the undefined value will be read.

Команда U-Boot для чтения регистра

Bit fields structure

typedef union  pg_dat
{
  struct
  {
   unsigned pg_dat : 20;
   unsigned unused0 : 12;
  } b;
   unsigned long w;
} PG_DAT