USB3317C_V01 datasheet(40/76 Pages) SMSC

40 / 76 page

Hi-Speed USB Transceiver with 1.8V-3.3V ULPI Interface - 26MHz Reference Clock

Datasheet

Revision 2.1 (06-02-10)

SMSC USB3317 REV

DATASHEET

6.2.3

ULPI RXCMD

The ULPI Link needs information which was provided by the following pins in a UTMI implementation:

linestate[1:0], rxactive, rxvalid and rxerror. When implementing the OTG functions the VBUS and ID

pin states must also be transferred to the Link.

ULPI defines a Receive Command Byte (RXCMD) that contains this information. The Encoding of the

RXCMD byte is given in the Table 6.3.

Transfer of the RXCMD byte occurs in Synchronous Mode when the PHY has control of the bus. The

ULPI Protocol Block shown in Figure 6.1 determines when to send an RXCMD. When a linestate

change occurs, the RXCMD is sent immediately if the DIR output is low.

When a USB Receive is occurring, RXCMD’s are sent whenever NXT = 0 and DIR = 1. During a USB

Transmit, the RXCMD’s are returned to the Link after STP is asserted.

To summarize a RXCMD transfer occurs:

When DIR is low and a linestate change occurs.

When Vbus and/or ID comparators change state.

During a USB receive when NXT is low.

After STP is asserted during a USB transmit command.

After the USB3317 deasserts DIR and STP is low during start-up

After the USB3317 exits Low Power Mode, Serial Modes, or Carkit Modes after detecting that the

Link has asserted STP.

Figure 6.6 ULPI Extended Register Read in Synchronous Mode

DIR

CL K

D A T A [7 :0 ]

ST P

NX T

T X D CM D

ex te n d ed r e g r e a d

Id le

Re g D a t a

Tu r n a r ou n d

Tu r n a r ou nd

T 2

Id le

Ex te n d e d

ad d r ess

USB3317C Datasheet(PDF) 40 Page - SMSC Corporation