User Guide

RM-94

Nokia Customer Care 7 - System Module

28 COMPANY CONFIDENTIAL Issue 1 04/2005

Table 7: System connector interface description

ACI

ACI (Accessory Control Interface) is a point-to-point, Master-Slave, bi-directional serial bus.

ACI has two main features:

• The identification of accessory type is provided

• The insertion and removal detection of an accessory device

• Acting as a data bus, intended mainly for control purposes.

FBUS

FBUS is an asynchronous data bus having separate TX and RX signals. Default bit rate of the

bus is 115.2 Kbit/s. FBUS is mainly used for controlling the phone in the interface to PC via

DKU-5.

VOUT

The VOUT pin delivers the power supply for PopPort

accessories, which are using the ACI

or FBUS. The voltage level is 2.78V / 70mA.

Pin # Signal Notes

1 VCHAR

2 GND Charge ground

3 ACI Insertion & removal detection /

Serial data bi-directional 1 kbit/s

4 Vout Power supply for external accessories

5 Not used in RM-94

6 FBUS_RX Serial data from accessory to phone /

115 kbit/s

7 FBUS_TX Serial data from phone to accessory /

115 kbit/s

8 GND Data ground

9 XMIC N Negative audio in signal

10 XMIC P Positive audio in signal

11 HSEAR N Negative audio out signal.

12 HSEAR P Positive audio out signal.

13 HSEAR RN Negative audio out signal.

14 HSEAR RP Positive audio out signal.