USB3450 Standard Microsystems Corporation, USB3450 Datasheet - Page 28

• Manufacturer Part Number: USB3450
• Description: Hi-speed USB HOST OR Device PHY WITH Utmi+interface
• Manufacturer: Standard Microsystems Corporation

Revision 0.1 (05-11-05)
7.3
7.4
7.5
MODE[1:0]
HI-SPEED TEST MODES
10
11
Test_Packet
SE0_NAK
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 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
USB3450 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.
For FS operation, IDLE is a J state on the bus. SE0 is used as part of the EOP or to indicate reset.
When asserted in an EOP, SE0 is never asserted for more than 2 bit times. The assertion of SE0 for
more than 2.5us is interpreted as a reset by the device operating in FS mode.
For HS operation, IDLE is a SE0 state on the bus. SE0 is also used to reset a HS device. A HS
device cannot use the 2.5us assertion of SE0 (as defined for FS operation) to indicate reset since the
bus is often in this state between packets. If no bus activity (IDLE) is detected for more than 3ms, a
HS device must determine whether the downstream facing port is signaling a suspend or a reset. The
following section details how this determination is made. If a reset is signaled, the HS device will then
initiate the HS Detection Handshake protocol.
If a device in HS mode detects bus inactivity for more than 3ms (T1), it reverts to FS mode. This
enables the FS pull-up on the DP line in an attempt to assert a continuous FS J state on the bus. The
Link must then check LINESTATE for the SE0 condition. If SE0 is asserted at time T2, then the
upstream port is forcing the reset state to the device (i.e., a Driven SE0). The device will then initiate
the HS detection handshake protocol.
Test Mode Support
SE0 Handling
Reset Detection
K
J
STATE#
2
3
Disable Bit Stuffing
and NRZI encoding
Reserved
STATE NAME
OPERATIONAL MODE
Table 7.2 Operational Modes (continued)
Table 7.3 Hi-Speed Test Modes
State 0
State 2
State 2
State 0
DATASHEET
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
N/A
28
LINK TRANSMITTED
USB3450 SETUP
Test Packet data
Hi-Speed USB Host or Device PHY With UTMI+ Interface
No transmit
All '1's
All '0's
DATA
DESCRIPTION
XCVRSELECT &
TERMSELECT
HS
HS
HS
HS
SMSC USB3450
Datasheet