7643 datasheet(222/424 Pages) RENESAS

222 / 424 page

Rev.2.00

Aug 28, 2006

page 101 of 202

7643 Group

REJ09B0133-0200

APPLICATION

2.6 USB

q Device request

The SETUP transaction in the setup stage of a control transfer is called a device request. The

device request defines the format of its data phase.

When type is standard (0): Standard device request

This is the basic device request necessary for all USB devices.

When type is class (1): Class device request

Device class is defined by the USB Implementers Forum (USB IF). The USB IF also determines

the requested configuration and class request.

Please refer to the Full-Speed USB2.0 specification for more details on each data format.

q Bulk transfer

Bulk IN transfer

The bulk IN transfer, which transmits data from the device to host CPU, continually repeats IN

transactions. The 7643 MCU issues a data packet in response to an IN token. When the data

is not transmitted successfully, the MCU sends one of the following responses.

- No response if the received IN token is broken.

- STALL handshake is returned if 7643 Group is stalled.

- NAK packet is returned if there is no transmit data in the IN FIFO.

Bulk OUT Transfer

The bulk OUT transfer, which transmits data from the host CPU to the device, continually

repeats OUT transactions.

When the 7643 MCU receives a data packet successfully, an ACK packet is returned. A successful

receive is the state in which there is no bit-stuffing error or CRC error, and the data PID was

received correctly.

DATA0 and DATA1 of data packet of next data phase are toggled during the handshake phase

of each transaction if the ACK packet sent by the receive side is received successfully by the

transmit side.

The 7643 MCU transmits the following responses when data is not successfully received.

- No response if the received data is broken.

- STALL handshake is returned if 7643 Group is stalled.

- ACK packet is returned if inconsistency of sequence bit in received data.

- NAK packet is returned if the 7643 Group OUT FIFO is full.

For more details, refer to the Full-Speed USB2.0 specification.

q Interrupt transfer

The interrupt transfer format is the same as that of the bulk transfer.

7643 Datasheet(PDF) 222 Page - Renesas Technology Corp