DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 565

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

(5) Status Stage (Control-Out)
The control-out status stage starts with an IN token from the host. When an IN-token is
received at the start of the status stage, there is not yet any data in the EP0i FIFO, and so an
EP0i transfer request interrupt is generated. The firmware recognizes from this interrupt that
the status stage has started. Next, in order to transmit 0-byte data to the host, 1 is written to the
EP0i packet enable bit but no data is written to the EP0i FIFO. As a result, the next IN token
causes 0-byte data to be transmitted to the host, and control transfer ends.
After the firmware has finished all processing relating to the data stage, 1 should be written to
the EP0i packet enable bit.
Transfer 0-byte data to host
(EP0iTS in UIFR0 = 1)
End of control transfer
Receive IN token
Set EP0i transmit
in EP0i FIFO?
complete flag
Valid data
USB function
Figure 14.16 Status Stage Operation (Control-Out)
Yes
ACK
No
NAK
EXIRQx
EXIRQx
Rev.7.00 Dec. 24, 2008 Page 511 of 698
request interrupt enable bit
(EP0iPKTE in UTRG0 = 1)
(EP0iTRE in UIER0 = 0)
Write 0 to EP0i transfer
(EP0iTR in UIFR0 = 0)
Write 1 to EP0i packet
(EP0iTS in UIFR0 = 0)
End of control transfer
Clear EP0i transmit
Clear EP0i transfer
Firmware
complete flag
request flag
enable bit
REJ09B0074-0700