at43usb320a ATMEL Corporation, at43usb320a Datasheet - Page 76

• Manufacturer Part Number: at43usb320a
• Description: Full-speed Usb Microcontroller With An Embedded Hub
• Manufacturer: ATMEL Corporation

Interrupt/Bulk IN
Transfers at Function
Endpoint
Interrupt/Bulk OUT
Transfers at Function
Endpoint EP1 and 2
76
AT43USB320A
The firmware must first condition the endpoint through the Endpoint Control Register,
FENDP1/2_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
u n til it su c ce s sf u lly r e ce iv e s a n AC K fr o m th e h o st . F ina lly , th e FI U cle a r s th e
TX_PACKET_READY bit and asserts a TX_COMPLETE interrupt.
1. Read UISR
2. Read FCSR1/2
3. Clear TX_COMPLETE
4. Set UIAR[FEP1/2 INTACK] to clear the interrupt source
The firmware must first condition the endpoint through the Endpoint Control Register,
FENDP1/2_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. Read FIFO
4. Clear RX_OUT
5. Set UIAR[FEP1/2 INTACK] to clear the interrupt source
Set endpoint direction: set EPDIR
Set interrupt or bulk: EPTYPE = 11 or 10
Enable endpoint: 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
Set endpoint direction: clear EPDIR
Set interrupt or bulk: EPTYPE = 11 or 10
Enable endpoint: set EPEN
If more data:
Wait for RX_OUT interrupt
If no more data: set DATA END
1443E–USB–4/04