Freescale Semiconductor MC68HC08KH12 manual 124

SOFF — Start Of Frame Detect Flag

This read only bit is set when a valid SOF PID is detected on the D0+ and D0– lines at the root port. Software must clear this flag by writing a logic 1 to SOFFR bit in the SIETSR register. Reset clears this bit. Writing to SOFF has no effect.

1 = Start Of Frame PID has been detected

0 = Start Of Frame PID has not been detected

EOF2F — The second E nd Of Frame Point Flag

This read only bit is set when the internal frame timer counts to the bit time that the hub must see upstream traffic terminated near the end of frame. This bit time is defined as 10 bit times from the next Start of Frame PID. Software must clear this flag by writing a logic 1 to EOF2FR bit in the SIETSR register. Reset clears this bit. Writing to EOF2F has no effect.

1 = Frame timer counts to the EOF2 point

0 = Frame timer does not count to the EOF2 point

EOPF — End of Packet Detect Flag

This read only bit is set when a valid End-of-Packet sequence is detected on the D0+ and D0– lines. Software must clear this flag by writing a logic 1 to the EOPFR bit in the SIETSR register. Reset clears this bit. Writing to EOPF has no effect.

1 = End-of-Packet sequence has been detected

0 = End-of-Packet sequence has not been detected

TRANF — Bus Signal Tr ansition Detect Flag

This read only bit is set if there is any bus activity on the upstream or the downstream data lines. Generally speaking, this bit is used to wakeup the suspended hub when there is any bus activity occurred. Software must clear this flag by writing a logic 1 to the TRANFR bit in the SIETSR register. Reset clears this bit. Writing to TRANF has no effect.

1 = Signal transition has been detected

0 = Signal transition has not been detected

Advance Information	MC68HC(7)08KH12 — Rev. 1.1
124	Freescale Semiconductor