AM / FM / Aux Circuitry
Refer to Figure 4-14. The bottom Sub board contains the analog signal processing and the input / output
connectors. The choice of what is heard is input to IC501, this data is transferred along TXD / RXD lines
(CN3002/pins 21 and 23) to CPU IC1010. IC1010 (main board) initiates the overall action by:
1. Determining what input the user has selected.
2. Outputs data to instruct the appropriate ICs to operate that mode.
3. Instruct IC301 (SA data/clock at CN3002/pins 40 and 42) to select AM, FM, Aux or the digital input (IC301/pin
40 and 41).
4. Unmute the audio (CN3002/pin 24).
Customer settings to the audio (e.g. equalizer, tone, level, etc) used by IC301 (servo board) are actually stored
in the EEPROM IC4002 on main board. They are copied from IC4002 into IC301 at power ON.
M CLK
L R CLK
IC4001
DSP
B CLK
MAIN
ADDRESS
DATA BUS
IC4002
EE PROM
MAIN BOARD
SDO
2
IC371
D/A
16
CONV.
L
3
7
R
1
8
13
SO
14
CLK
15
CS
DATA
200
159
IC1010
CLK
CPU
190
178
168
MUTE
SUB
TXD RXD
CN3002/526
FIGURE 4-14 - ANALOG AUDIO PROCESS
SUB BOARD
MUTE
L
4 7
3
1
IC372
R
LPF
4 5
5
7
TUX101
AM/FM
TUNER
4 0
SA DATA /CLK
4 2
CLK
DATA
2 4
D MUTE
IC501
2 1
SYSTEM
2 3
CONTROL
2 6
C
2 8
CLK
SO
3 0
49
4. Car Music Storage Unit
2
IC301
VOL
4
MUTE
SEL
28
40
27
41
26
25
9
AM
24
FM
12
21
22
LINE MUTE
5
IC304
POWER
9
22
X MUTE
AMP
TDA7386
FACE PLATE
BUTTONS
AUX
IN
LF
LR
RF
LINE
OUT
RR
SW
(BLK)
4 SPEAKER OUTPUT
FL +/-
FR +/-
RL +/-
RR +/-
16A125 1526
11/15/02