Product manual

Spinpoint M9TU-USB 3.0 Product Manual REV 1.0
45
USB INTERFACE AND USB COMMANDS
6.3.5 Transfer/Endpoint Types
The Universal Serial Bus specification defines four transfer/endpoint types,
• Control Transfers
• Interrupt Transfers
• Isochronous Transfers
• Bulk Transfers
■ Control Transfer
- Packet Length: 8bytes (Low), 8, 16, 32 or 64bytes (High), 64bytes (Full)
- Stage
- SetUp Stage: SETUP->DATA 0->ACK Packet
- Optional Data Stage: IN (Data transmit), OUT (Control need) Packet
- Status Stage: IN/OUT packet for reports the status of the overall
- Command/Status Operation.
ex) Device Setup data transfer
■ Interrupt Transfer
- Guaranteed Latency
- Stream Pipe - Unidirectional
- Error detection and next period retry
- Maximum data payload size: 8bytes (Low), 64bytes (Full), 1024bytes (High)
ex) Mouse, JoyStick, Keyboard
■ Isochronous Transfer
- Guaranteed access to USB bandwidth
- Bounded latency
- Stream Pipe - Unidirectional
- Error detection via CRC, but no retry or guarantee of delivery
- Full & high speed modes only
- No data toggling
- Maximum data payload size: 1023bytes (Full), 1024bytes (High)
ex) Audio, Telephone
■ Bulk Transfer
- Used to transfer large bursty data
- Error detection via CRC, with guarantee of delivery
- No guarantee of bandwidth or minimum latency
- Stream Pipe - Unidirectional
- Full & high speed modes only
- Maximum bulk packet size - 8, 16, 32 or 64bytes (Full), up to 512bytes (High)
- Large Data Operation
ex) Print, Scanner, Still Camera