AT43USB355M-AC ATMEL [ATMEL Corporation], AT43USB355M-AC Datasheet - Page 80

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

Interrupt/Bulk IN
Transfers at Function
End-point
Interrupt/Bulk OUT
Transfers at Function
End-point EP1, 2 and 3
80
AT43USB355
The firmware must first condition the end-point through the End-point Control Register, FEND-
P1/2/3_CNTR:
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. Read UISR
2. Read FCSR1/2/3
3. Clear TX_COMPLETE
4. Set UIAR[FEP1/2/3 INTACK] to clear the interrupt source
The firmware must first condition the end-point through the End-point Control Register, FEND-
P1/2/3_CNTR:
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. Read UISR
2. Read FCSR1/2/3
3. Read FIFO
4. Clear RX_OUT
5. Set UIAR[FEP1/2/3 INTACK] to clear the interrupt source
Set end-point direction: set EPDIR
Set interrupt or bulk: EPTYPE = 11 or 10
Enable end-point: set EPEN
If more data: fill FIFO, set TX Packet Ready
Wait for TX_COMPLETE interrupt
If no more data: set DATA END in FCAR1/2/3
Set end-point direction: clear EPDIR
Set interrupt or bulk: EPTYPE = 11 or 10
Enable end-point: set EPEN
If more data:
Wait for RX_OUT interrupt
If no more data: set DATA END
2603G–USB–04/06