User's Manual

HC864-AUTO Hardware User Guide
1vv0300946 Rev.4 – 2012-12-27
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Reserved. Page 50 of 77
10. USB Port
The HC864-AUTO module includes a Universal Serial Bus (USB) transceiver, which
operates at USB low-speed (1.5Mbits/sec), USB full-speed (12Mbits/sec) and USB high-
speed (480Mbits/sec).
It is compliant with the USB 2.0 specification and can be used for diagnostic monitoring,
control and data transfers.
The USB_DPLUS and USB_DMINUS signals have a clock rate of 480MHz. The signal
traces should be routed carefully. Trace lengths, number of vias and capacitive loading should
be minimized. The impedance value should be as close as possible to 90 Ohms differential.
The table below describes the USB interface signals:
TIP:
HC864-AUTO does NOT support host device operation at the moment, that is, it works as a
slave device. Consequently USB_ID must be opened (not connected).
Signal
HC864-ATUO
Pad No.
Usage
USB_VBUS 48 Power sense for the internal USB transceiver
USB_D- 80
Minus (-) line of the differential, bi-directional USB signal to/from the
peripheral device
USB D+ 79
Plus (+) line of the differential, bi-directional USB signal to/from the
peripheral device
USB_ID
(for future use)
35
Analog input used to sense whether a peripheral device is
connected and if connected, to determine the peripheral type, host or
slave