Read Sony XR-1790 Service Manual online
– 26 –
5-7.
IC PIN FUNCTION DESCRIPTION
•
MAIN BOARD IC1 LC72322N-9400 (SYSTEM CONTROLLER)
Pin No.
Pin Name
I/O
Function
1
XIN
I
System clock input terminal (4.5 MHz)
2
TEST2
I
Connected to ground
3
NC
I
Not used (fixed at “H”)
4
AM-SD
I
AM signal meter voltage detection input from the FM/AM tuner unit (TU100) “H” active
5
FM-SD
I
FM signal meter voltage detection input from the FM/AM tuner unit (TU100) “H” active
6
STEREO
I
Stereo detection signal input from the FM/AM tuner unit (TU100) (Commonly used for stereo
display input) FM stereo detection at input of “L”
display input) FM stereo detection at input of “L”
7
MOTOR
O
Capstan/reel motor (M901) drive signal output “H”: motor on
8
AMP-MUTE2
O
Muting control signal output to the power amplifier (IC500) “L”: muting on
9
MW/SW
O
MW/SW selection signal output terminal “H”: MW, “L”: SW Not used (fixed at “H”)
10
—
O
Not used (open)
11
BEEP
O
Beep sound signal output terminal “H” active
12
POWER-ON
O
Power on/off control signal output “H”: power on
13
ILL-ON
O
Power on/off control signal output for the liquid crystal display driver (IC900), illumination lamp
and back light lamp “H”: power on
and back light lamp “H”: power on
14
N/R
I
Tape direction switch (S901) input terminal “H”: forward side, “L”: reverse side
15
TAPE-IN
I
Tape in detection switch (S903) input terminal “L”: tape in
16
FF-REW
I
FF/REW detection switch (S902) input terminal “L”: FF/REW mode
17
K1
I
Key matrix return signal input terminal Not used (fixed at “L”)
18
K0
I
Key matrix return signal input for the frequency select switch (S1)
Used for the E model only
Used for the E model only
19
AMP-ON
O
Standby on/off signal output to the power amplifier (IC500) “L”: standby, “H”: amp on
20
SEEK
O
Seek control signal output to the FM/AM tuner unit (TU100) “H” active
Used for the E model only
Used for the E model only
21
SEEK
O
Seek control signal output to the FM/AM tuner unit (TU100) “L” active
Used for the US and Canadian models only
Used for the US and Canadian models only
22
LOCAL/DX
O
Local/DX selection signal output to the FM/AM tuner unit (TU100) “L”: DX, “H”: local
23, 24
—
O
Not used (open)
25
T2
O
Key matrix scan signal output for the frequency select switch (S1)
Used for the E model only
Used for the E model only
26
T1
O
27
T0
O
28
VOL-CE
O
Chip enable signal output to the electrical volume (IC450) “H” active
29
VOL-DI
O
Serial data output to the electrical volume (IC450) “H” active
30
VOL-CL
O
Serial data transfer clock signal output to the electrical volume (IC450)
31
VDD
—
Power supply terminal (+5V)
32
MUTE-REQ
I
Muting request signal input terminal (“H” active) “L”: accessory on, “H”: accessory off
33
BAND-KEY
I
TUNER switch (S900) input terminal “L” is input when pressing the switch
34
PANEL-IN
I
Detects the removal of the attaching and removing type front panel block “L”: attaching
Not used (open)
Not used (open)
35
NC
I
Not used (fixed at “L”)
36 to 40
—
O
Not used (open)
41
MUTE
O
Audio muting on/off control signal output terminal “H”: muting on Not used (open)
42
—
O
Not used (open)
43
AMP-MUTE
O
Amp muting on/off control signal output terminal “L”: muting on Not used (open)
44
ANT-REM
O
Control signal output for the external power antenna and external amplifier “H” active
Key matrix scan signal output terminal Not used (open)
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