USB INTERFACE
IO-U These pins connect to the USB bus data
USB Bus
Data
USB-
USB+
signals.
USB
Transceiver
Filter
LOOPFLTR
This pin provides the ability to supplement the
internal filtering of the transceiver with an
external network, if required.
USB
Transceiver
Bias
RBIAS
A 9.09 Kohm precision resistor is attached
from ground to this pin to set the transceiver’s
internal bias currents.
Termination RTERM
Resistor
A precision 1.5Kohm precision resistor is
attached to this pin from a 3.3V supply.
Full Speed
USB Data
FS-
FS+
IO-U
These pins connect to the USB- and USB+
pins through 31.6 ohm series resistors.
MEMORY/IO INTERFACE
Memory Data MD[7:0]
Bus
IO12
These signals are used to transfer data
between the internal CPU and the external
program memory.
Memory
Address Bus
MA[15:0]
O12
O12
O12
O12
O12
These signals address memory locations
within the external memory.
Memory Write nMWR
Strobe
Program Memory Write; active low
Program Memory Read; active low
XDATA space Read; active low
XDATA space Write; active low
Memory Read nMRD
Strobe
IO Read
Strobe
nIOR
IO Write
Strobe
nIOW
SMSC DS – USB97C201
Page 11
Rev. 03/25/2002
PRELIMINARY
SMSC [ SMSC CORPORATION ]
