Регистры H616: OHCI Frame Interval Register

31 |•|•|•|•|•|•|•|•|•|•|•|•|•|•|•|•| 16
15 |•|•|•|•|•|•|•|•|•|•|•|•|•|•|•|•| 00

FRAME_INTERVAL_TOGGLER

Bit 31
R/W (R)
0x0

HCD toggles this bit whenever it loads a new value to FrameInterval.

FS_LARGEST_DATA_PACKET

Bits 30 : 16
R/W (R)
0x0

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.

Unused

Bits 15 : 14

FRAME_INTERVAL

Bits 13 : 0
R/W (R)
0x2edf

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.

HCD (HC)

Bit fields structure

typedef union o_hcfminterval { struct { unsigned frame_interval : 14; unsigned unused0 : 2; unsigned fs_largest_data_packet : 15; unsigned frame_interval_toggler : 1; } b; unsigned long w; } O_HcFmInterval