Хост-контроллер USB2.0: список регистров

  CCED_31_4

CCED[31:4]

The pointer is advanced to the next ED after serving the present one.
HC will continue processing the list from where it left off in the last Frame.
When it reaches the end of the Control list, HC checks the ControlListFilled of in HcCommandStatus.
If set, it copies the content of HcControlHeadED to HcControlCurrentED and clears the bit.
If not set, it does nothing.
HCD is allowed to modify this register only when the ControlListEnable of HcControl is cleared.
When set, HCD only reads the instantaneous value of this register.
Initially, this is set to zero to indicate the end of the Control list.

  CCED_3_0

CCED[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_hccontrolcurrented
{
  struct
  {
   unsigned cced_3_0 : 4;
   unsigned cced_31_4 : 28;
  } b;
   unsigned long w;
} O_HcControlCurrentED