User Guide

NMM-3 Company Confidential
7 - System Module & UI CCS Technical Documentation
Page 7-22 Copyright  2003 Nokia Corporation Issue 1 (11/2003)
Company Confidential
The Nokia USB device solution is supported using the Wireless 2 Function Controller
(W2FC) core block in the TIKU ASIC. The core completes several USB functions automati-
cally and is controlled by the ARM9 MCU.
NUT (D300)provides the interface between the ASIC's 1.8 V bus and the 3.3 V USB data
bus.
Nokia USB Transceiver (NUT) is fully compliant with the Universal Serial Bus Specifica-
tion Rev. 1.1.
NUT is able to transmit and receive serial data at both full-speed. In NMM-3, its low-
speed (1.5 Mbit/s) capability is only used in SE (single ended) mode in production loop-
back test. FBUS is not supported on NMM-3
External Audio
The NMM-3 is designed to support fully differential external accessories connecting via
the Pop-Port system connector. Features supported are:
• 4-Wire fully differential stereo audio output.
• 2-Wire differential mic input.
• ACI for detection and data interface.
External Microphone Connection
The external microphone input is fully differential lines are connected to UEME micro-
phone inputs MIC2N and MIC2P. The UEME (MICB2) provides the bias voltage. Micro-
phone input lines are ESD protected.
A short circuit between the headset microphone signals generates a HOOKINT signal.
When the accessory is not connected, a pull-up resistor internal to UEME holds the
HOOKINT line to VFLASH1 (2.8V). When the accessory is connected the voltage on
HOOKINT drops to 1.8V due to the bias current flowing through the 1KΩ ASIP resistors
R415. When the button is pressed the microphone signals are connected together, and
the HOOKINT input will get half of the mic bias DC value 1.1V. This change in the DC
level will cause the HOOKINT comparator to change state, in this case from 0 to 1. The
button can be used for answering in coming calls, but not to initiate outgoing calls.