SMSC USB3280 - Manual (Page 29)

Hi-Speed USB Device PHY with UTMI Interface
Datasheet
SMSC USB3280 29 Revision 1.5 (11-15-07)
DATASHEET
8.2 OPMODES
The OPMODE[1:0] pins allow control of the operating modes.
The OPMODE[1:0] signals are normally changed only when the transmitter and the receiver are
quiescent, i.e. when entering a test mode or for a device initiated resume.
When using OPMODE[1:0] = 10 (state 2), OPMODES are set, and then 5 60MHz clocks later,
TXVALID is asserted. In this case, the SYNC and EOP patterns are not transmitted.
The only exception to this is when OPMODE[1:0] is set to state 2 while TXVALID has been asserted
(the transceiver is transmitting a packet), in order to flag a transmission error. In this case, the
USB3280 has already transmitted the SYNC pattern so upon negation of TXVALID the EOP must also
be transmitted to properly terminate the packet. Changing the OPMODE[1:0] signals under all other
conditions, while the transceiver is transmitting or receiving data will generate undefined results.
Under no circumstances should the device controller change OPMODE while the DP/DM lines are still
transmitting or unpredictable changes on DP/DM are likely to occur. The same applies for
TERMSELECT and XCVRSELECT.
8.3 Test Mode Support
Table 8.2 Operational Modes
MODE[1:0] STATE# STATE NAME DESCRIPTION
00 0 Normal Operation Transceiver operates with normal USB data encoding and
decoding
01 1 Non-Driving Allows the transceiver logic to support a soft disconnect feature
which tri-states both the HS and FS transmitters, and removes
any termination from the USB making it appear to an upstream
port that the device has been disconnected from the bus
10 2 Disable Bit Stuffing
and NRZI encoding Disables bitstuffing and NRZI encoding logic so that 1's loaded
from the DATA bus become 'J's on the DP/DM and 0's become
'K's
11 3 Reserved N/A
Table 8.3 USB 2.0 Test Modes
USB 2.0 TEST MODES
USB3280 SETUP
OPERATIONAL MODE SIE TRANSMITTED DATA
XCVRSELECT &
TERMSELECT
SE0_NAK State 0 No transmit HS
J State 2 All '1's HS
K State 2 All '0's HS
Test_Packet State 0 Test Packet data HS