Datasheet

831
SAM9G45 [DATASHEET]
Atmel-6438O-ATARM-SAM9G45-Datasheet_08-Dec-15
37.5.3 USB Transfer Event Definitions
A transfer is composed of one or several transactions.
Notes: 1. Control transfer must use endpoints with one bank and can be aborted using a stall handshake.
2. Isochronous transfers must use endpoints configured with two or three banks.
An endpoint handles all transactions related to the type of transfer for which it has been configured.
37.5.4 USB V2.0 High Speed BUS Transactions
Each transfer results in one or more transactions over the USB bus.
There are five kinds of transactions flowing across the bus in packets:
1. Setup Transaction
2. Data IN Transaction
3. Data OUT Transaction
4. Status IN Transaction
5. Status OUT Transaction
Table 37-3. USB Transfer Events
Transfer
TransactionDirection Type
CONTROL (bidirectional) Control
(1)
Setup transaction → Data IN transactions → Status OUT transaction
Setup transaction → Data OUT transactions → Status IN transaction
Setup transaction → Status IN transaction
IN (device toward host)
Bulk IN
Data IN transaction → Data IN transactionInterrupt IN
Isochronous IN
(2)
OUT (host toward device)
Bulk OUT
Data OUT transaction → Data OUT transactionInterrupt OUT
Isochronous OUT
(2)