Usb (Universal Serial Bus); How The Usb Interface Works - Nokia 6265 Baseband Description And Troubleshooting

6265/6265i/6268 (RM-66)
Baseband Description and Troubleshooting

USB (Universal Serial Bus)

How the USB Interface Works

The Wireless 2 Function Controller (W2FC) core completes several USB functions
automatically and is controlled by the ARM9 MCU. The Nokia USB Transceiver (NUT)
provides the interface between the ASIC's 1.8 V bus and the 3.3 V USB bus. In addition,
NUT is capable of transmitting and receiving Fbus signals to and from the Fbus UART in
D2800. NUT is able to transmit and receive serial data at full-speed (12 Mbit/s). The USB
signal ESD protection and line matching resistance, and USB pull-up resistor is included
to the USB ASIP. This component also includes ESD protection for VOUT and ACI system
connector pins.
When the mobile terminal is connected to a computer using a DKU-2 data cable, the
computer will provide Vbus (5V) to and pull down D+ a,d D – lines. The mobile terminal
will respond by pulling the D+ line high. The computer acknowledges and starts
transferring data at 12Mbits/sec.
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Figure 18: USB interface block diagram
©2005 Nokia Corporation
Company Confidential Issue 1 11/2005