User Guide

NSD-5
3. System Module PAMS Technical Documentation
Page 38 Nokia Corporation Issue 1 05/02
Table 10: Serial port timing
System/Accessory Interface
Description
External accessory interface specifies a connector and set of signals that allow the phone
to be used with a variety of standard peripherals (See Figure 21 following).
XEAR, XMICP, XMICN, EAD_HEADINT, and SGND are used to connect hands-free, headset,
and other accessories that require analog audio signal connections.
The VIN is used for battery charging.
Figure 21: External accessory interface
Signal Definitions
The interface signals include XEAR, XMICP, XMICN, EAD_HEADINT, SGND, L_GND, and
VIN. The function of these signals are defined as follows:
XEAR Audio output signal to the external speaker on the HFU or headset
SGND Audio output return (ground) path
XMICP External microphone input
XMICN External microphone input return (ground) path
EAD_HEADINT External audio accessory interrupt input to MAD4
Tsdis Data in setup to rising edge 10 ns
Tsdih Data in hold from rising edge 10 ns
Parameters Definition Minimum Maximum Unit