Nokia RH-6 Series Baseband Description & Troubleshooting page 39

CCS Technical Documentation
8. MBUS is disconnected from HeadInt line (MBUS switch). After every communication.
9. Accessory is removed (no insertion & removal resistor on ACI line) --> phone gets
HeadInt interrupt from ACI line low to high transition.
9a) If no HeadInt interrupt comes in the next 100ms the accessory is really removed and
the phone goes in the state "no accessory".
Signal
V
FLASH1
V
head
Specified values
for levels
V
ACI_detect
V
high
V
low
Signal flow on ACI line - Non ACI-ASIC accessory inserted
V
headInt
V
FLAS H1
V
head_m in
V
low
1. Accessory is connected (insertion & removal resistor connect to ACI line)
1a) phone gets HeadInt interrupt after 20ms check that ACI line is still low (<Vhead min)
2. Connect MBUS with HeadInt line (MBUS switch)
3. The 20 ms timer elapsed and no transition has been on HeadInt line
3a) Disconnect MBUS from HeadInt line
4. Accessory is removed. Phone gets HeadInt interrupt from ACI line low to high transi-
tion.
4a) If no HeadInt interrupt comes in the next 100ms the accessory is really removed.
FBUS
FBUS is an asynchronous data bus with separate TX and RX signals. Default bit rate of
the bus is 115.2 Kbit/s.
Issue 1 10/2003
Company Confidential
Table 18: Voltage Levels
Min Typ Max
2.7 2.78 2.86
1.75 1.9 2.05
Min Typ Max
0.83 1.13
2.45 2.71
<0.22*VDD
1
20ms
2 3
a a
1 3
Figure 21: Signal flow on ACI Line
© 2003 Nokia Corporation.
6 - BB Description & Troubleshooting
Unit Note
V
V
Unit Note
V Voltage level if MBUS not connected
to HeadInt (MBUS switch open), but
ACI accessory is inserted.
V Voltage level after MBUS connected to
HeadInt.
V
M ono H eadset is
recognized.
RH-6
a
4
4
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