Datasheet

Table Of Contents
Section 15 Universal Serial Bus Interface (USB)
Page 566 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
15.5.7 Bulk-Out Transfer (Dual FIFOs) (EP2o Is specified as Endpoint)
EP2o has two 64-byte FIFOs, but the user can perform data reception and receive data reads
without being aware of this dual-FIFO configuration.
When one FIFO is full after reception is completed, the UIFR1/EP2oREADY 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/EP2oRDFN bit. This operation empties the FIFO that has just been
read, and makes it ready to receive the next packet.