IN token sent
?
received
STALL
No
Yes
Yes
No
RxStall set
ReqPkt cleared
Error Count cleared
Interrupt generated
Problem in
data sent
Yes
?
Data0/1
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
ReqPkt cleared
Error Count cleared
Interrupt generated
Yes
Implies problem
at peripheral end
of connection.
Transaction deemed
complete
For each IN packet
requested in SETUP phase
ReqPkt
set
?
No
ACK sent
RxPktRdy
set
ReqPkt cleared
Error Count cleared
Interrupt generated
Architecture
1348
SPRUH91D – March 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Serial Bus 2.0 (USB) Controller
Figure 31-11. IN Data Phase Flow Chart