Register Descriptions
1379
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Universal Serial Bus (USB) Controller
18.5.35 USB Transmit Control and Status Endpoint n High Register (USBTXCSRH[1]-
USBTXCSRH[15])
The USB transmit control and status endpoint
n
high 8-bit registers (USBTXCSRH[
n
]) provide additional
control for transfers through the currently selected transmit endpoint.
For the specific offset for each register see
.
Mode(s):
OTG A or Host
OTG B or Device
The USBTXCSRH[
n
] registers in OTG A/Host Mode are shown in
and described in
Figure 18-43. USB Transmit Control and Status Endpoint n High Register (USBTXCSRH[n])
in OTG A/Host Mode
7
6
5
4
3
2
1
0
AUTOSET
Reserved
MODE
DMAEN
FDT
DMAMOD
DTWE
DT
R/W-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; -
n
= value after reset
Table 18-46. USB Transmit Control and Status Endpoint n High Register (USBTXCSRH[n])
in OTG A/Host Mode Field Descriptions
Bit
Field
Value
Description
7
AUTOSET
Auto Set
0
The TXRDY bit must be set manually.
1
Enables the TXRDY bit to be automatically set when data of the maximum packet size (value in
USBTXMAXP[
n
]) is loaded into the transmit FIFO. If a packet of less than the maximum packet size is
loaded, then the TXRDY bit must be set manually.
6
Reserved
0
Reserved
5
MODE
Mode
Note:
This bit only has an effect when the same endpoint FIFO is used for both transmit and receive
transactions.
0
Enables the endpoint direction as RX.
1
Enables the endpoint direction as TX.
4
DMAEN
DMA Request Enable
Note:
Three TX and three /RX endpoints can be connected to the
μ
DMA module. If this bit is set for a
particular endpoint, the DMAATX, DMABTX, or DMACTX field in the USB DMA Select (USBDMASEL)
register must be programmed correspondingly.
0
Disables the
μ
DMA request for the transmit endpoint.
1
Enables the
μ
DMA request for the transmit endpoint.
3
FDT
Force Data Toggle
0
No effect
1
Forces the endpoint DT bit to switch and the data packet to be cleared from the FIFO, regardless of
whether an ACK was received. This bit can be used by interrupt transmit endpoints that are used to
communicate rate feedback for isochronous endpoints.
Note:
This bit should only be set when the TXRDY bit is set. At other times, it may cause data to be
corrupted.
2
DMAMOD
DMA Request Mode
Note:
This bit must not be cleared either before or in the same cycle as the above DMAEN bit is
cleared.
0
An interrupt is generated after every
μ
DMA packet transfer.
1
An interrupt is generated only after the entire
μ
DMA transfer is complete.
Note:
This bit is valid only when the endpoint is operating in Bulk or Interrupt mode.
1
DTWE
Data Toggle Write Enable. This bit is automatically cleared once the new value is written.
0
The DT bit cannot be written.
1
Enables the current state of the transmit endpoint data to be written (see DT bit).