AT43USB353M datasheet(63/95 Pages) ATMEL

63 / 95 page

AT43USB353M

3307B–USB–4/04

Interrupt/Bulk IN

Transfers at Function

End-point

The firmware must first condition the end-point through the End-point Control Register, FEND-

P1/2/3_CNTR:

Set end-point direction: set EPDIR

Set interrupt or bulk: EPTYPE = 11 or 10

Enable end-point: 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

unti l i t su c ces sf ull y rece i v es an AC K fr om the host . F i na l l y , the F I U cl ears th e

TX_PACKET_READY bit and asserts a TX_COMPLETE interrupt.

Read UISR

Read FCSR1/2/3

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 FCAR1/2/3

Set UIAR[FEP1/2/3 INTACK] to clear the interrupt source

Interrupt/Bulk OUT

Transfers at Function

End-point EP1, 2 and 3

The firmware must first condition the end-point through the End-point Control Register, FEND-

P1/2/3_CNTR:

Set end-point direction: clear EPDIR

Set interrupt or bulk: EPTYPE = 11 or 10

Enable end-point: 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 FCSR1/2/3

Read FIFO

Clear RX_OUT

If more data:

Wait for RX_OUT interrupt

If no more data: set DATA END

Set UIAR[FEP1/2/3 INTACK] to clear the interrupt source

AT43USB353M Datasheet(PDF) 63 Page - ATMEL Corporation