AT43USB355M-AC ATMEL [ATMEL Corporation], AT43USB355M-AC Datasheet - Page 77

• Manufacturer Part Number: AT43USB355M-AC
• Description: Full-speed USB Microcontroller with Embedded Hub, ADC and PWM
• Manufacturer: ATMEL [ATMEL Corporation]

No-data Status
Response State
Control Read Data
Response State
2603G–USB–04/06
The Function Interface Unit receives an IN token from the Host. The FIU responds with a zero
length DATA1 packet until receiving an ACK from the host, then asserts a TX_COMPLETE
interrupt.
The Function Interface Unit receives an IN token from the Host. The FIU responds with NAKs
until TX_PACKET_READY is set. The FIU then sends the data in the FIFO upstream, retrying
until it successfully receives an ACK from the host. Finally, the FIU clears the
TX_PACKET_READY bit and asserts a TX_COMPLETE interrupt.
1. IN token from Host
2. Send DATA1(0)
3. ACK from Host
4. Set TX COMPLETE → INT
1. IN token from Host
2. a. If TX Packet Ready = 1, send
3. ACK from Host
4. Clear TX Packet Ready
b. If TX Packet Ready = 0, send NAK
Set TX Complete → INT
DATA0/DATA1
Hardware
Hardware
Repeat steps 1 through 8
5. Read UISR
6. Read CSR0
7. If SET ADDRESS, program the new
8. Clear TX_COMPLETE, clear Data
9. Set UIAR[EP0 INTACK]
5. Read UISR
6. Read CSR0
7. Clear TX COMPLETE in CAR0:
8. Set UIAR[EP0 INTACK] to clear
Address, set ADD_EN bit
End, set Force STALL in CAR0
a. If more data: fill FIFO, set TX
Packet Ready, set DIR in CAR0
b. If no more data: set Force STALL,
set DATA END in CAR0
interrupt source
Firmware
Firmware
AT43USB355
77