DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 569

• 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

14.5.7
EP2 has two 64-byte FIFOs, but the user can receive data and read receive data without being
aware of this dual-FIFO configuration.
When one FIFO is full after reception is completed, the UIFR1/EP2READY bit is set. After the
first receive operation into one of the FIFOs when both FIFOs are empty, the other FIFO is empty,
and so the next packet can be received immediately. When both FIFOs are full, NAK is returned to
the host automatically. When reading of the receive data is completed following data reception, 1
is written to the UTRG0/EP2RDFN bit. This operation empties the FIFO that has just been read,
and makes it ready to receive the next packet.
Bulk-Out Transfer (Dual FIFOs) (Endpoint 2)
Clear EP2 data ready status
(EP2READY in UIFR1 = 1)
(EP2READY in UIFR1 = 0)
Set EP2 data ready status
Receive data from host
Receive OUT token
EP2 FIFOs empty?
in EP2 FIFO?
USB function
Figure 14.19 EP2 Bulk-Out Transfer Operation
Space
Both
Yes
Yes
ACK
NAK
No
No
EXIRQx
EXIRQI
Rev.7.00 Dec. 24, 2008 Page 515 of 698
Read data from USB endpoint
Read USB endpoint receive
data size register 2 (UESZ2)
(EP2RDFN in UTRG0 = 1)
data register 2 (UEDR2)
Write 1 to EP2o read
complete bit
Firmware
REJ09B0074-0700