Renesas H8S/2158 User Manual page 634

Section 18 Universal Serial Bus Interface (USB)
Bit Bit Name Initial Value R/W
0 EP0OTF 0
Note: * Only 0 can be written to clear the flag.
Rev. 3.00 Jan 25, 2006 page 580 of 872
REJ09B0286-0300
Description
R/(W) * Endpoint 0 Host Output Transfer Failure Flag
Indicates that the endpoint 0 host output transfer has
been completed abnormally.
Endpoint 0 host output transfer has two transactions:
OUT transaction and SETUP transaction. Data
transmission in these transactions are the same, but flag
handling in these transactions differ.
Since most of the commands sent by a SETUP
transaction are processed in the USB function core, the
EP0OTS flag in TSFR0 is not set and the EP0OTF flag
is set to 1. For a command that cannot be processed in
the USB core, the EP0OTS flag is set to 1. Note that
neither the EP0OTS nor the EP0OTF flag is set to 1 if
the SEICNT bit in USBMDCR is set to 1 regardless of
whether the command can be processed in the USB
core or not.
0: Indicates that the endpoint 0 is in a transfer wait state.
[Clearing conditions]
•
0 is written to EP0OTF after EP0OTF = 1 has been
read.
•
Endpoint 0 has received a SETUP token.
1: Indicates that the endpoint 0 host output transfer
(OUT transaction or SETUP transaction) has been
completed abnormally.
[Setting conditions]
•
Data cannot be sent because the FIFO is full after an
OUT token has been received.
•
Data cannot be sent because EP0OTC = 0 after an
OUT token has been received (NAK transmission).
•
A communication error occurs after the OUT token
has been received.
•
A received command can be processed in the USB
function core (only when the SETICNT bit is cleared
to 0) after a SETUP token has been received.