17.5.28 USB Control and Status Endpoint 0 Low Register (USBCSRL0), offset 0x102
The USB control and status endpoint 0 low 8-bit register (USBCSRL0) provides control and status bits for
endpoint 0.
Mode(s):
Host
Device
USBCSRL0 in Host mode is shown in
and described in
.
Figure 17-34. USB Control and Status Endpoint 0 Low Register (USBCSRL0) in Host Mode
7
6
5
4
3
2
1
0
NAKTO
STATUS
REQPKT
ERROR
SETUP
STALLED
TXRDY
RXRDY
R/W-0
R/W-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 17-35. USB Control and Status Endpoint 0 Low Register(USBCSRL0) in Host Mode Field
Descriptions
Bit
Field
Value
Description
7
NAKTO
NAK Timeout. Software must clear this bit to allow the endpoint to continue.
0
No timeout
1
Indicates that endpoint 0 is halted following the receipt of NAK responses for longer than the time set
by the USBNAKLMT register.
6
STATUS
Status Packet. Setting this bit ensures that the DT bit is set in the USBCSRH0 register so that a DATA1
packet is used for the STATUS stage transaction.
0
No transaction
1
Initiates a STATUS stage transaction. This bit must be set at the same time as the TXRDY or REQPKT
bit is set.
This bit is automatically cleared when the STATUS stage is over.
5
REQPKT
Request Packet. This bit is cleared when the RXRDY bit is set.
0
No request
1
Requests an IN transaction.
4
ERROR
Error. Software must clear this bit.
0
No error
1
Three attempts have been made to perform a transaction with no response from the peripheral. The
EP0 bit in the USBTXIS register is also set in this situation.
3
SETUP
Setup Packet. Setting this bit always clears the DT bit in the USBCSRH0 register to send a DATA0
packet.
0
Sends an OUT token.
1
Sends a SETUP token instead of an OUT token for the transaction. This bit should be set at the same
time as the TXRDY bit is set.
2
STALLED
Endpoint Stalled. Software must clear this bit.
0
No handshake has been received.
1
A STALL handshake has been received.
1
TXRDY
Transmit Packet Ready. If both the TXRDY and SETUP bits are set, a setup packet is sent. If just
TXRDY is set, an OUT packet is sent.
0
No transmit packet is ready.
1
Software sets this bit after loading a data packet into the TX FIFO. The EP0 bit in the USBTXIS
register is also set in this situation.
Universal Serial Bus (USB) Controller
1102
TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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