Field Name Bits Default HCD HC Description
BCED 31:4 0000000
h
RW RW
BulkCurrentED
This is advanced to the next ED after the HC has
served the present one. HC continues processing the
list from where it left off in the last Frame. When it
reaches the end of the Bulk list, HC checks the
ControlListFilled of HcControl. If set, it copies the
content of HcBulkHeadED to HcBulkCurrentED and
clears the bit. If it is not set, it does nothing. HCD is
only allowed to modify this register when the
BulkListEnable of HcControl is cleared. When set,
the HCD only reads the instantaneous value of this
register. This is initially set to zero to indicate the end
of the Bulk list.
HcDoneHead - 32 bits - [MEM_Reg : 30h] Field Name Bits Default HCD HC Description
Reserved 3:0 Reserved
DH 31:4 0b R RW
DoneHead
When a TD is completed, HC writes the content of
HcDoneHead to the NextTD field of the TD. HC then
overwrites the content of HcDoneHead with the
address of this TD. This is set to zero whenever HC
writes the content of this register to HCCA. It also
sets the WritebackDoneHead of HcInterruptStatus.
HcFmInterval - 32 bits - [MEM_Reg : 34h] Field Name Bits Default HCD HC Description
FI 13:0 2EDFh RW R
FrameInterval
This specifies the interval between two consecutive
SOFs in bit times. The nominal value is set to be
11,999.
HCD should store the current value of this field before
resetting HC. By setting the HostControllerReset
field of HcCommandStatus as this will cause the HC
to reset this field to its nominal value. HCD may
choose to restore the stored value upon the
completion of the Reset sequence.
Reserved 15:14 Reserved
FSMPS 30:16 0000h RW R
FSLargestDataPacket This field specifies a value which is loaded into the
Largest Data Packet Counter at the beginning of
each frame. The counter value represents the largest
amount of data in bits which can be sent or received
by the HC in a single transaction at any given time
without causing scheduling overrun. The field value is
calculated by the HCD.
FIT 31 0b RW R
FrameIntervalToggle
HCD toggles this bit whenever it loads a new value to
FrameInterval