Datasheet

Section 15 Universal Serial Bus Interface (USB)
REJ09B0140-0900 Rev. 9.00 Page 593 of 846
Sep 16, 2010
H8S/2215 Group
15.9.7 EP3o Isochronous Transfer
• Reception of EP3o data larger than the maximum packet size
The EP3o data FIFO cannot receive data with size larger than the maximum packet size; the
excessive data is lost. In this case, the receive size register
3o (UESZ3o) can count up to the
maximum packet size and the EP3o abnormal transfer flag (EP3oTF) is set to 1.
Figure 15.34 shows the 10-byte data reception when the maximum packet size is specified as 9
bytes.
Data (1)
Data (2)
Data (3)
Data (4)
Data (5)
Data (6)
Data (7)
Data (8)
Data (9)
Data (10)
Count up to maximum
packet size
Data storage
Set the EP3o abnormal
transfer flag
EP3o FIFO
UESZ3o
H'09
Store data items within the
maximum packet size
Exessive data items are lost
Data (1)
Data (2)
Data (3)
Data (4)
Data (5)
Data (6)
Data (7)
Data (8)
Data (9)
UIFR1/EP3oTF
1
Figure 15.34 10-Byte Data Reception