Universal Serial Bus OTG Controller
UG0331 User Guide Revision 15.0
320
10.3.6.6 TX_CSRL_REG (in Peripheral mode) Bit Definitions
10.3.6.7 TX_CSRL_REG (in Host mode) Bit Definitions
Table 217 •
TX_CSRL_REG (Peripheral)
Bit
Number
Name
Reset
Value
Function
7
IncompTx
0
When the endpoint is being used for high-bandwidth ISO transfers, this bit is
set to indicate where a large packet has been split into 2 or 3 packets for
transmission but insufficient IN tokens have been received to send all the
parts.
In anything other than ISO transfers, this bit will always return 0.
6
ClrDataTog
0
The Cortex-M3 processor (or fabric master) writes a 1 to this bit to reset the
endpoint data toggle to 0.
5
SentStall
0
This bit is set when a STALL handshake is transmitted. The FIFO is flushed
and the TxPktRdy bit (bit 0 of this register) is cleared. The Cortex-M3
processor (or fabric master) should clear this bit.
4
SendStall
0
The Cortex-M3 processor (or fabric master) writes a 1 to this bit to issue a
STALL handshake to an IN token. The Cortex-M3 processor (or fabric master)
clears this bit to terminate the stall condition.
This bit has no effect where the endpoint is being used for ISO transfers.
3
FlushFIFO
0
The Cortex-M3 processor (or fabric master) writes a 1 to this bit to flush the
latest packet from the endpoint TX FIFO. The FIFO pointer is reset, the
TxPktRdy bit (bit0 of this register) is cleared and an interrupt is generated. It
Mmay be set simultaneously with TxPktRdy to abort the packet that is currently
being loaded into the FIFO.
FlushFIFO should only be used when TxPktRdy is set. At other times, it may
cause data to be corrupted. Also note that, if the FIFO is double-buffered,
FlushFIFO may need to be set twice to completely clear the FIFO.
2
UnderRun
0
The controller sets this bit if an IN token is received when TxPktRdy (bit0 of
this register) is not set. The Cortex-M3 processor (or fabric master) should
clear this bit.
1
FIFONotEmpty
0
The controller sets this bit when there is at least 1 packet in the transmit FIFO.
0
TxPktRdy
0
The Cortex-M3 processor (or fabric master) sets this bit after loading a data
packet into the FIFO. It is cleared automatically when a data packet has been
transmitted. An interrupt is generated at this point (if enabled). TxPktRdy is
automatically cleared prior to loading a second packet into a double-buffered
FIFO.
Table 218 •
TX_CSRL_REG (Host)
Bit
Number
Name
Reset
Value
Function
7
NAK Timeout
0
(Bulk endpoints only
) This bit will be set when the transmit endpoint is halted,
following the receipt of responses for longer than the time set as the NAK Limit
by the TxInterval register. The Cortex-M3 processor (or fabric master) should
clear this bit to allow the endpoint to continue.
IncompTx
0
(High-bandwidth interrupt endpoints only
) This bit will be set if no response is
received from the device to which the packet is being sent.
6
ClrDataTog
0
The Cortex-M3 processor (or fabric master) writes a 1 to this bit to reset the
endpoint data toggle to 0.