Advertisement
(3)
Data Stage (Control-Out)
Data reception from host
The application first analyzes command data from the host in the setup stage, and determines the
subsequent data stage direction. If the result of command data analysis is that the data stage is out-
transfer, the application waits for data from the host, and after data is received (EP0oTS bit in
IFR0 = 1), reads data from the FIFO. Next, the application writes 1 to the EP0o read complete bit,
empties the receive FIFO, and waits for reception of the next data.
The end of the data stage is identified when the host transmits an IN token and the status stage is
entered.
USB function
OUT token reception
1 written
No
to TRG.EP0s
RDFN?
NAK
Yes
ACK
Set EP0o reception
Interrupt request
complete flag
(IFR0.EP0o TS = 1)
OUT token reception
1 written
No
to TRG.EP0o
RDFN?
NAK
Yes
Figure 22.12 Data Stage (Control-Out) Operation
Section 22 USB Function Module (USB)
Application
Clear EP0o reception
complete flag
(IFR0.EP0o TS = 0)
Read data from EP0o
receive data size register
(EPSZ0o)
Read data from EP0o
data register (EPDR0o)
Write 1 to EP0o read
complete bit
(TRG.EP0o RDFN = 1)
Rev. 1.00 Mar. 12, 2008 Page 875 of 1178
REJ09B0403-0100
Advertisement
