Accessory Control Interface (Aci) - Nokia RH-6 Series Baseband Description & Troubleshooting

CCS Technical Documentation
Pin #
11
12
13
14

Accessory Control Interface (ACI)

ACI is a point-to-point, master-slave, and bi-directional serial bus. It has three features:
• The insertion and removal detection of an accessory device
• Acting as a data bus, intended mainly for control purposes
• 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 no plug is present, the pull-up resistor 100k pulls up the HeadInt signal
to VFLASH1. If the accessory is inserted, the external "insertion & removal" resistor works
as voltage divider and decrease the voltage level below the threshold Vhead.
Thereby the comparator output will be changed to high state causing an interrupt.
If the plug is removed, the voltage level of HeadInt increases again to VFLASH1. This
voltage level is higher than the threshold of the comparator and thereby its output will
be changed to low. This changes is leading to an interrupt.
These HeadInt interrupts are initiated the accessory detection or removal sequence.
If no accessory inserted / connected the only active part on the Pop-port interface is the
ACI line.
Issue 1 10/2003
Company Confidential
Table 17: System connector interface description
Signal
HSEAR N Negative audio out signal.
Max bandwidth from the phone
HSEAR P Positive audio out signal.
Max bandwidth from the phone
Not used in RH-6
Not used in RH-6
© 2003 Nokia Corporation.
6 - BB Description & Troubleshooting
Notes
RH-6
Page 37