Registers
1723
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Serial Bus 2.0 (USB) Controller
34.4.38 Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
The control status register for peripheral receive endpoint (PERI_RXCSR) is shown in
and
described in
Figure 34-64. Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
15
14
13
12
11
10
8
AUTOCLEAR
ISO
DMAEN
DISNYET
DMAMODE
Reserved
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
7
6
5
4
3
2
1
0
CLRDATATOG
SENTSTALL
SENDSTALL
FLUSHFIFO
DATAERROR
OVERRUN
FIFOFULL
RXPKTRDY
W-0
R/W-0
R/W-0
W-0
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write only; -
n
= value after reset
Table 34-68. Control Status Register for Peripheral Receive Endpoint (PERI_RXCSR)
Field Descriptions
Bit
Field
Value
Description
15
AUTOCLEAR
0
DMA Mode: The CPU sets the AUTOCLEAR bit prior to enabling the Rx DMA.
1
CPU Mode: If the CPU sets the AUTOCLEAR bit, then the RXPKTRDY bit will be automatically
cleared when a packet of RXMAXP bytes has been unloaded from the Receive FIFO. When
packets of less than the maximum packet size are unloaded, RXPKTRDY will have to be cleared
manually.
14
ISO
0-1
Set this bit to enable the Receive endpoint for Isochronous transfers, and clear it to enable the
Receive endpoint for Bulk/Interrupt transfers.
13
DMAEN
0-1
Set this bit to enable the DMA request for the Receive endpoints.
12
DISNYET
0
DISNYET: Applies only for Bulk/Interrupt Transactions: The CPU sets this bit to disable the sending
of NYET handshakes. When set, all successfully received Rx packets are ACK'd including at the
point at which the FIFO becomes full.
Note: This bit only has any effect in high-speed mode, in which mode it should be set for all
Interrupt endpoints.
1
PID_ERROR: Applies only for ISO Transactions: The core sets this bit to indicate a PID error in the
received packet.
11
DMAMODE
0-1
Always clear this bit to 0.
10-8
Reserved
0
Reserved
7
CLRDATATOG
0-1
Write a 1 to this bit to reset the endpoint data toggle to 0.
6
SENTSTALL
0-1
This bit is set when a STALL handshake is transmitted. The FIFO is flushed and the TXPKTRDY bit
is cleared. You should clear this bit.
5
SENDSTALL
0-1
Write a 1 to this bit to issue a STALL handshake. Clear this bit to terminate the stall condition.
Note: This bit has no effect where the endpoint is being used for Isochronous transfers.
4
FLUSHFIFO
0-1
Write a 1 to this bit to flush the next packet to be read from the endpoint Receive FIFO. The FIFO
pointer is reset and the RXPKTRDY bit is cleared.
Note: FLUSHFIFO has no effect unless RXPKTRDY is set. Also note that, if the FIFO is double-
buffered, FLUSHFIFO may need to be set twice to completely clear the FIFO.
3
DATAERROR
0-1
This bit is set when RXPKTRDY is set if the data packet has a CRC or bit-stuff error. It is cleared
when RXPKTRDY is cleared.
Note: This bit is only valid when the endpoint is operating in ISO mode. In Bulk mode, it always
returns zero.
2
OVERRUN
0-1
This bit is set if an OUT packet cannot be loaded into the Receive FIFO. You should clear this bit.
Note: This bit is only valid when the endpoint is operating in ISO mode. In Bulk mode, it always
returns zero.
1
FIFOFULL
0-1
This bit is set when no more packets can be loaded into the Receive FIFO.
0
RXPKTRDY
0-1
This bit is set when a data packet has been received. You should clear this bit when the packet has
been unloaded from the Receive FIFO. An interrupt is generated when the bit is set.