HD6417641 RENESAS [Renesas Technology Corp], HD6417641 Datasheet - Page 828

• Manufacturer Part Number: HD6417641
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 20 USB Function Module
20.4.6
Rev. 4.00 Sep. 14, 2005 Page 778 of 982
REJ09B0023-0400
Note: This flowchart shows just one example of interrupt transfer processing. Other possibilities include an
EP3 Interrupt-IN Transfer
operation flow in which, if there is data to be transferred, the EP3 DE bit in the USB data status register
is referenced to confirm that the FIFO is empty, and then data is written to the FIFO.
Data transmission to host
(USBIFR1/EP3 TS = 1)
Set EP3 transmission
IN token reception
Figure 20.12 EP3 Interrupt-IN Transfer Operation
in EP3 FIFO?
USB function
complete flag
Valid data
Yes
ACK
NACK
No
Interrupt request
Write data to USBEP3 data
Write data to USBEP3 data
(USBTRG/EP3 PKTE = 1)
(USBTRG/EP3 PKTE = 1)
Clear EP3 transmission
(USBIFR1/EP3 TS = 0)
register (USBEPDR3)
Write 1 to EP3 packet
register (USBEPDR3)
Write 1 to EP3 packet
for transmission
for transmission
complete flag
Is there data
Is there data
enable bit
enable bit
to host?
to host?
Application
Yes
Yes
No
No