
USB Registers
1746
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
27.5.40 USBTXCSRLn Register [reset = 0x0]
USB Transmit Control and Status Endpoint 1 Low (USBTXCSRL1), offset 0x112
USB Transmit Control and Status Endpoint 2 Low (USBTXCSRL2), offset 0x122
USB Transmit Control and Status Endpoint 3 Low (USBTXCSRL3), offset 0x132
USB Transmit Control and Status Endpoint 4 Low (USBTXCSRL4), offset 0x142
USB Transmit Control and Status Endpoint 5 Low (USBTXCSRL5), offset 0x152
USB Transmit Control and Status Endpoint 6 Low (USBTXCSRL6), offset 0x162
USB Transmit Control and Status Endpoint 7 Low (USBTXCSRL7), offset 0x172
OTG A / Host
OTG B / Device
USBTXCSRLn is an 8-bit register that provides control and status bits for transfers through the currently
selected transmit endpoint.
USBTXCSRLn for OTG A / Host is shown in
and described in
.
USBTXCSRLn for OTG B / Device is shown in
and described in
.
Return to
Figure 27-47. USBTXCSRLn Register (OTG A / Host)
7
6
5
4
3
2
1
0
NAKTO
CLRDT
STALLED
SETUP
FLUSH
ERROR
FIFONE
TXRDY
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R/W-0x0
Table 27-52. USBTXCSRLn Register Field Descriptions (OTG A / Host)
Bit
Field
Type
Reset
Description
7
NAKTO
R/W
0x0
NAK Time-out.
0x0 = No time-out.
0x1 = Bulk endpoints only:
Indicates that the transmit endpoint is halted following the receipt of
NAK responses for longer than the time set by the NAKLMT field in
the USBTXINTERVALn register.
Software must clear this bit to allow the endpoint to continue.
6
CLRDT
R/W
0x0
Clear Data Toggle.
Writing a 1 to this bit clears the DT bit in the USBTXCSRHn register.
5
STALLED
R/W
0x0
Endpoint Stalled.
Software must clear this bit.
0x0 = A STALL handshake has not been received.
0x1 = Indicates that a STALL handshake has been received. When
this bit is set, any USB DMA request that is in progress is stopped,
the FIFO is completely flushed, and the TXRDY bit is cleared.
4
SETUP
R/W
0x0
Setup Packet.
Setting this bit also clears the DT bit in the USBTXCSRHn register.
0x0 = No SETUP token is sent.
0x1 = Sends a SETUP token instead of an OUT token for the
transaction. This bit should be set at the same time as the TXRDY
bit is set.