LM3S5D56 Datasheet, PDF (898/1146 Pages) Texas Instruments – Stellaris® LM3S5D56 Microcontroller

Universal Serial Bus (USB) Controller
Bit/Field
3
Name
DATAERR / NAKTO
Type
R/W
2
ERROR
R/W
1
FULL
RO
0
RXRDY
R/W
Reset
0
Description
Data Error / NAK Timeout
Value Description
0 Normal operation.
1 Isochronous endpoints only: Indicates that RXRDY is set and
the data packet has a CRC or bit-stuff error. This bit is cleared
when RXRDY is cleared.
Bulk endpoints only: Indicates that the receive endpoint is halted
following the receipt of NAK responses for longer than the time
set by the NAKLMT field in the USBRXINTERVALn register.
Software must clear this bit to allow the endpoint to continue.
0
Error
Value Description
0 No error.
1 Three attempts have been made to receive a packet and no
data packet has been received. The EPn bit in the USBRXIS
register is set in this situation.
Software must clear this bit.
Note:
This bit is only valid when the receive endpoint is operating
in Bulk or Interrupt mode. In Isochronous mode, it always
returns zero.
0
FIFO Full
Value Description
0 The receive FIFO is not full.
1 No more packets can be loaded into the receive FIFO.
0
Receive Packet Ready
Value Description
0 No data packet has been received.
1 A data packet has been received. The EPn bit in the USBRXIS
register is also set in this situation.
If the AUTOCLR bit in the USBRXCSRHn register is set, then the this bit
is automatically cleared when a packet of USBRXMAXPn bytes has
been unloaded from the receive FIFO. If the AUTOCLR bit is clear, or if
packets of less than the maximum packet size are unloaded, then
software must clear this bit manually when the packet has been unloaded
from the receive FIFO.
898
January 23, 2012
Texas Instruments-Production Data