SMSC USB3250 - Manual (Page 5)

Hi-Speed USB Device Transceiver with UTMI Interface
SMSC USB3250 5 Revision 1.7 (05-11-07)
PRODUCT PREVIEW
Pin Description Tables
Table 1 System Interface Pins
NAME DIRECTION
ACTIVE
LEVEL DESCRIPTION
RESET Input High Reset. Reset all state machines. After coming out of reset, must
wait 5 rising edges of clock before asserting TXValid for transmit.
Assertion of Reset: May be asynchronous to CLKOUT.
De-assertion of Reset: Must be synchronous to CLKOUT unless
RESET is asserted longer than two periods of CLKOUT.
XCVRSELECT Input N/A Transceiver Select. This signal selects between the FS and HS
transceivers:
0: HS transceiver enabled
1: FS transceiver enabled.
TERMSELECT Input N/A Termination Select. This signal selects between the FS and HS
terminations:
0: HS termination enabled
1: FS termination enabled
SUSPENDN Input Low Suspend. Places the transceiver in a mode that draws minimal
power from supplies. Shuts down all blocks not necessary for
Suspend/Resume operation. While suspended, TERMSELECT
must always be in FS mode to ensure that the 1.5k Ω pull-up on
DP remains powered.
0: Transceiver circuitry drawing suspend current
1: Transceiver circuitry drawing normal current
CLKOUT Output Rising Edge System Clock. This output is used for clocking receive and
transmit parallel data at 60MHz (8-bit mode) or 30MHz (16-bit
mode). When in 8-bit mode, this specification refers to CLKOUT
as CLK60. When in 16-bit mode, CLKOUT is referred to as
CLK30.
OPMODE[1:0] Input N/A Operational Mode. These signals select between the various
operational modes:
[1] [0] Description
0 0 0: Normal Operation
0 1 1: Non-driving (all terminations removed)
1 0 2: Disable bit stuffing and NRZI encoding
1 1 3: Reserved
LINESTATE[1:0] Output N/A Line State. These signals reflect the current state of the USB
data bus in FS mode, with [0] reflecting the state of DP and [1]
reflecting the state of DM. When the device is suspended or
resuming from a suspended state, the signals are combinatorial.
Otherwise, the signals are synchronized to CLKOUT.
[1] [0] Description
0 0 0: SE0
0 1 1: J State
1 0 2: K State
1 1 3: SE1
DATABUS16_8 Input N/A Databus Select. Selects between 8-bit and 16-bit data transfers.
0: 8-bit data path enabled. VALIDH is undefined. CLKOUT =
60MHz.
1: 16-bit data path enabled. CLKOUT = 30MHz.