Хост-контроллер USB2.0: список регистров

  HCD_31_4

EHCD[31:4]
The HcControlHeadED register contains the physical address of the first
Endpoint Descriptor of the Control list.
HC traverse the Control list starting with the HcControlHeadED pointer.
The content is loaded from HCCA during the initialization of HC.

  EHCD_3_0

EHCD[3:0]
Because the general TD length is 16 bytes, the memory structure for the TD must be aligned to a 16-byte boundary.
So the lower bits in the PCED, through bit 0 to bit 3 must be zero in this field.

HCD (HC)

Команда U-Boot для чтения регистра

Bit fields structure

typedef union  o_hccontrolheaded
{
  struct
  {
   unsigned ehcd_3_0 : 4;
   unsigned hcd_31_4 : 28;
  } b;
   unsigned long w;
} O_HcControlHeadED