
Specification
NET2270 USB Interface Controller
______________________________________________________________________________
NetChip Technology, Inc., 2003
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490
FAX (650) 526-1494
http://www.netchip.com
Rev 3.6, April 17, 2003
17
2.3
Clocks, Reset, Misc. (9 pins)
Signal Name
Pin
Type
Description
XIN
11
I
Oscillator input. Connect to 30 MHz crystal or external oscillator
module.
XOUT
12
O
Oscillator output. Connect to crystal, or leave open if using an external
oscillator module. The oscillator stops when the device is suspended.
LCLKO
35
O,
12mA,
TP
Local Clock Output. This pin is a buffered clock output from the internal
PLL, with the frequency depending on the state of the Local Clock Output
field in the LOCCTL configuration register. This pin stops oscillating as
soon as the NET2270 is put into suspend mode, and is not driven while
the device is suspended.
When the internal oscillator is started, LCLKO
is prevented from being driven for 2 msec. LCLKO doesn’t oscillate
while the RESET# pin is asserted or when the chip is in the power-down
mode.
RESET#
43
I, S, PU
Reset. External reset. Connect to local or power-on reset. To reset when
oscillator is stopped (initial power-up or in suspend state), assert for at
least two milliseconds. When oscillator is running, assert for at least five
60 MHz clock periods.
VBUS
48
I, S
USB VBUS. This input indicates when the NET2270 is connected to a
powered-up USB host connector. An external 47K pull-down resistor
should be connected to this pin to keep it low when not connected to the
USB.
TEST1
1
I
TEST1 mode. Connect to ground for normal operation.
TEST2
2
I
TEST2 mode. Connect to ground for normal operation.
TEST3
64
I
TEST3 mode. Connect to ground for normal operation.
SMC
3
I
Scan Mode Control. Connect to VDD for normal operation.