AT43USB326 datasheet(52/102 Pages) ATMEL

52 / 102 page

AT43USB326

3313D–USB–04/06

Interrupt/Bulk IN

Transfers at Function

Endpoint

The firmware must first condition the endpoint through the Endpoint Control Register,

FENDP1/2_CNTR:

Set endpoint direction: set EPDIR

Set interrupt or bulk: EPTYPE = 11 or 10

Enable endpoint: set EPEN

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

un til it s ucce ssfu lly rece ives a n ACK fr om the h os t. Fin ally, th e FIU clea rs th e

TX_PACKET_READY bit and asserts a TX_COMPLETE interrupt.

Read UISR

Read FCSR1/2

Clear TX_COMPLETE

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 UIAR[FEP1/2 INTACK] to clear the interrupt source

Interrupt/Bulk OUT

Transfers at Function

Endpoint EP1 and 2

The firmware must first condition the endpoint through the Endpoint Control Register,

FENDP1/2_CNTR:

Set endpoint direction: clear EPDIR

Set interrupt or bulk: EPTYPE = 11 or 10

Enable endpoint: set EPEN

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.

Read UISR

Read FCSR1/2

Read FIFO

Clear RX_OUT

If more data:

Wait for RX_OUT interrupt

If no more data: set DATA END

Set UIAR[FEP1/2 INTACK] to clear the interrupt source

AT43USB326 데이터시트(PDF) 52 Page - ATMEL Corporation