USB3503 Evaluation Board Manual
SMSC USB3503 EVB
8
Revision 1.0 (08-22-11)
USER MANUAL
4.1
Digital Control
The RESET_N and HUB_CONNECT pins can be controlled in real time with the
Digital Control
array.
Each button in the array corresponds to the pin with the matching name. When the button is orange,
the pin is at logic level High. When the button is black the voltage is a logic level Low. Refer to the
green box in
for the digital control array location.
Set the RESET_N pin low to reset the part and place it into the lowest power state. If the CONNECT
pin is low when the RESET pin transitions from low to high, the USB3503 will remain in a state that
allows the serial interface registers to be manipulated. To enumerate the hub, either write 00h to
register E7h, or drive the CONNECT pin high by pressing the CONNECT button in the Digital Control.
Once the USB3503 has enumerated, the serial interface registers should not be modified.
Notes:
To prevent the Aardvark from driving against another voltage, the Aardvark is running in an
Open/Drain mode, therefore it is important that all switches on the board pull the pins up to
the Vcc value.
4.2
I
2
C Communication
The application also contains a general I
2
C register read/write section. The
Bit
and
Description
display the serial interface register descriptions found in the USB3503 datasheet. The
Register
display
can be used to select the proper serial interface register to manipulate. Click on the
Value
or
Bit
box
above to change the value of the register. Once the desired value and register are selected, press the
Write
button to change the value on the part. Click on the
Read
button and the
Value
and
Bit
boxes
will update the current value on the part. Refer to the USB3503 datasheet for a detailed description of
each register and operation of the device
Figure 4.3 Digital Control (Green) and I
2
C (Yellow) sections
