For each OUT packet
specified in SETUP phase
TxPktRdy
set
?
OUT token sent
DATA0/1 packet sent
?
received
Stall
No
Yes
Yes
No
RxStall set
TxPktRdy cleared
Error Count cleared
interrupt generated
Command could
not be completed
TxPktRdy cleared
Error Count cleared
Interrupt generated
Yes
?
No
ACK
received
Transaction
complete
No
NAK
received
?
Yes
?
NAK limit
reached
No
Yes
Error count
cleared
incremented
Error count
NAK Timeout set
Endpoint halted
Interrupt generated
?
Error
count=3
No
Error bit set
TxPktRdy cleared
Error Count cleared
interrupt generated
Yes
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
Architecture
1637
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Serial Bus 2.0 (USB) Controller
Figure 34-12. OUT Data Phase Flow Chart