User Guide

RH-25
System Module CCS Technical Documentation
Page 20 ©Nokia Corporation Confidential Issue 1 10/2003
System Connector (Tomahawk)
The 14-pin Tomahawk bottom connector consists of charging plug socket and Tomahawk
System Connector. Tomahawk system connector includes signals for the following:
Figure 15: Tomahawk bottom connector (charger plug socket and Tomahawk system connector)
Accessory Control Interface (ACI)
ACI is point-to-point, bi-directional serial bus. It has three main features:
1 The insertion and removal detection of an accessory device
2 Acting as a data bus, intended mainly for control purposes
3 The identification and authentication of accessory type which is connected
The accessories are detected by the HeadInt signal when the plug is inserted. Normally
when accessory is not present, the pull-up resistor 100k pulls up the HeadInt signal to
VFLASH1. If the accessory is inserted, the external resistor (located to accessory) works
as voltage divider and decreases the voltage level below the threshold of Vhead. Thereby
the comparator output will be changed to high state causing an interrupt.
If the accessory is removed, the voltage level of HeadInt increases again to VFLASH1.This
Table 5: Tomahawk system connector signals
Function Notes
Charging Pads for 2-wire charging in cradles
Audio 4-wire fully differential stereo audio output
2-wire differential microphone input
FM radio antenna connection
Power supply for accessories 2.78V/70mA output to accessories
ACI (Accessory Control Interface) Accessory detection/removal and controlling
FBUS Standard FBUS
DKU-5 (similar to USB) (optional) Power in 5V in from DKU-5 cable
XMIC N XMIC P
ACI
Charge GND
Fbus TX
Fbus RX
DATA GND
Shielding GND
HSEAR_L_P
HSEAR_L_N
N
Shielding GND
Charge
Vout
HSEAR_R_N HSEAR_R_P