Register Descriptions
1386
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Universal Serial Bus (USB) Controller
The USBCSRH[
n
] registers in OTG B/Device mode are shown in
and described in
Figure 18-49. USB Control and Status Endpoint n High Register (USBCSRH[n]) in OTG B/Device
Mode
7
6
5
4
3
2
0
AUTOCL
ISO
DMAEN
DISNYET /
PIDERR
DMAMOD
Reserved
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
LEGEND: R/W = Read/Write; -
n
= value after reset
Table 18-52. USB Control and Status Endpoint 0 High Register(USBCSRH[n])
in OTG B/Device Mode Field Descriptions
Bit
Field
Value
Description
7
AUTOCL
Auto Clear
0
No effect
1
Enables the RXRDY bit to be automatically cleared when a packet of USBRXMAXP[
n
] bytes has been
unloaded from the receive FIFO. When packets of less than the maximum packet size are unloaded,
RXRDY must be cleared manually. Care must be taken when using
μ
DMA to unload the receive FIFO
as data is read from the receive FIFO in 4-byte chunks regardless of the value of the MAXLOAD field in
the USBRXMAXP[
n
] register, see
6
ISO
Isochronous Transfers
0
Enables the receive endpoint for isochronous transfers.
1
Enables the receive endpoint for bulk/interrupt transfers.
5
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 DMAARX, DMABRX, or DMACRX field in the USB DMA Select (USBDMASEL)
register must be programmed correspondingly.
0
Disables the
μ
DMA request for the receive endpoint.
1
Enables the
μ
DMA request for the receive endpoint.
4
DISNYET/PI
DERR
Disable NYET / PID Error
0
No effect
1
For bulk or interrupt transactions: Disables the sending of NYET handshakes. When this bit is set, all
successfully received packets are acknowledged, including at the point at which the FIFO becomes full.
For isochronous transactions: Indicates a PID error in the received packet.
3
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.
0
Reserved
0
Reserved