AT43USB355M-AC ATMEL [ATMEL Corporation], AT43USB355M-AC Datasheet - Page 78

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

Control Read Status
Response State
Control Write Data
Response State
78
AT43USB355
The Function Interface Unit receives an OUT token from the Host with a zero length DATA1
packet. The FIU responds with a NAK until TX_COMPLETE is cleared. The FIU will then ACK
the retried OUT token from the Host and assert an RX_OUT interrupt.
The Function Interface Unit receives an OUT token from the Host with a DATA packet. The
FIU places the incoming data into the FIFO, issues an ACK to the host, and asserts an
RX_OUT interrupt.
1. OUT token from Host
2. DATA1(0) from Host
3. TX Complete = 0 ?
1. OUT token from Host
2. Put DATA0/DATA1 into FIFO
3. ACK to Host
4. Set RX OUT → INT
a. If yes, ACK to Host
Set RX OUT → INT
b. If no, NAK to Host
Hardware
Hardware
Repeat steps 1 through 9 until last DATA PACKET:
4. Read UISR
5. Read CSR0
6. Clear RX OUT, set Data End, set
7. Set UIAR[EP0 INTACK] to clear
5. Read UISR
6. Read CSR0
7. Read FIFO
8. Clear RX OUT
9. Set UIAR[EP0 INTACK] to clear the
Force Stall in H/FCAR0.
Note: A SETUP token will clear Data
End, therefore, it is not cleared by
FW in case Host retries.
interrupt source
If last data packet, set Force STALL,
set DATA END.
interrupt source
Firmware
Firmware
2603G–USB–04/06