at91cap7e ATMEL Corporation, at91cap7e Datasheet - Page 434

• Manufacturer Part Number: at91cap7e
• Description: Customizable Microcontroller
• Manufacturer: ATMEL Corporation

31.5.1.3
434
AT91CAP7E
USB Transfer Event Definitions
As indicated below, transfers are sequential events carried out on the USB bus.
Table 31-3.
Notes:
A status transaction is a special type of host-to-device transaction used only in a control transfer.
The control transfer must be performed using endpoints with no ping-pong attributes. According
to the control sequence (read or write), the USB device sends or receives a status transaction.
Control Transfers
Interrupt IN Transfer
(device toward host)
Interrupt OUT Transfer
(host toward device)
Isochronous IN Transfer
(device toward host)
Isochronous OUT Transfer
(host toward device)
Bulk IN Transfer
(device toward host)
Bulk OUT Transfer
(host toward device)
1. Setup Transaction
2. Data IN Transaction
3. Data OUT Transaction
1. Control transfer must use endpoints with no ping-pong attributes.
2. Isochronous transfers must use endpoints with ping-pong attributes.
3. Control transfers can be aborted using a stall handshake.
USB Transfer Events
(1) (3)
(2)
(2)
• Setup transaction > Data IN transactions > Status
• Setup transaction > Data OUT transactions > Status
• Setup transaction > Status IN transaction
• Data IN transaction > Data IN transaction
• Data OUT transaction > Data OUT transaction
• Data IN transaction > Data IN transaction
• Data OUT transaction > Data OUT transaction
• Data IN transaction > Data IN transaction
• Data OUT transaction > Data OUT transaction
OUT transaction
IN transaction
8549A–CAP–10/08