USB Device Controller
1584
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Universal Serial Bus (USB)
Table 29-47. DMA Receive Channels Configuration Register (RXDMA_CFG)
Field Descriptions (continued)
Bit
Field
Value
Description
3-0
RXDMA0_EP
Receive endpoint number for DMA channel 0. The endpoint number binary encoded in these four
bits is the current receive endpoint selected for DMA channel 0. A zero value indicates that the
DMA channel 0 is deactivated. Any other value automatically enables receive DMA transfer for the
selected endpoint.
0
Receive DMA channel 0 is deactivated.
1h
EP1
:
:
Fh
EP15
Values after system reset or USB reset are low (all 4 bits).
29.3.1.17 DMA Transmit Channels Configuration Register (TXDMA_CFG)
This read/write register enables the three possible DMA transmit channels and selects the endpoint
number that is assigned to each. An endpoint used by a TX DMA channel must have been configured
(through register EPn_TX). TXDMA_CFG register can be filled when SYSCON1.CFG_LOCK is set.
Only one channel is serviced at a time, so it is better to configure ISO endpoints on the first channel
(TXDMA0_EP). If, the/your ISO endpoint is configured on the channel 2 and it can never be serviced with
low software and a fast USB host.
USB device controller transmit endpoint DMA channels 0, 1, and 2 are associated with device controller
inputs.
Figure 29-44. DMA Transmit Channels Configuration Register (TXDMA_CFG)
[address = FCF78A22h]
15
13
12
11
8
Reserved
TX_REQ
TXDMA2_EP
R-0
R/W-0
R/W-0
7
4
3
0
TXDMA1_EP
TXDMA0_EP
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value at reset
Table 29-48. DMA Transmit Channels Configuration Register (TXDMA_CFG)
Field Descriptions
Bit
Field
Value
Description
15-13
Reserved
0
Reserved
12
TX_REQ
The TX DMA request active level or pulse bit allows the TXDMA request to be configurable level or
pulse-sensitive. When pulse-sensitive, the request is active for two cycles.
0
TX DMA request active level.
1
TX DMA request active pulse value after system reset or USB reset is low.
11-8
TXDMA2_EP
Transmit endpoint number for DMA channel 2: the endpoint number binary encoded in these four
bits is the current transmit endpoint selected for DMA channel 2. A zero value indicates that the
DMA channel 2 is deactivated. Any other value automatically enables transmit DMA transfer for the
selected endpoint.
0
Transmit DMA channel 2 is deactivated.
1h
EP1
:
:
Fh
EP15
Values after system reset or USB reset are low (all four bits).