21
5-7.
IC PIN FUNCTION DESCRIPTION
•
MAIN BOARD IC1 MN101C12GTF (SYSTEM CONTROLLER)
Pin No.
Pin Name
I/O
Description
1
VREF–
I
Reference voltage (0V) input terminal (for A/D converter)
2
—
I
Not used (fixed at “L”)
3
KEY-IN1
I
Key input terminal (A/D input) S909 to S920
(SHUF 2, REP 1, ENTER, MODE, DSPL, SEEK/AMS +
>
M
, PRST/DISC –, SOURCE,
DISC/PRST +, SEEK/AMS –
.
m
, SOUND, MENU keys input)
4
KEY-IN0
I
Key input terminal (A/D input) S901 to S906 (OFF, 3, 4, 5, 6, D-BASS keys input)
5, 6
—
I
Not used (fixed at “L”)
7
VSM
I
FM and AM signal meter voltage detection signal input from the FM/AM tuner unit (TU100)
(A/D input)
8, 9
—
I
Not used (fixed at “L”)
10
VREF+
I
Reference voltage (+5V) input terminal (for A/D converter)
11
VDD
—
Power supply terminal (+5V)
12
OSC2
O
Main system clock output terminal (18.432 MHz)
13
OSC1
I
Main system clock input terminal (18.432 MHz)
14
VSS
—
Ground terminal
15
XI
I
Sub system clock input terminal (32.768 kHz)
16
XO
O
Sub system clock output terminal (32.768 kHz)
17
MMOD
I
Not used (fixed at “L”)
18
TAPE-ON
O
Capstan/reel motor (M901) drive signal output terminal “H”: motor on
19
FF REW. IN
I
FF/REW detection signal input terminal “L”: FF/REW mode
20
TAPE IN
I
Tape in detection signal input terminal “L”: tape in
21
UNI-SO
O
Serial data output to the SONY bus interface (IC800)
22
UNI-SI
I
Serial data input from the SONY bus interface (IC800)
23
UNI-CKO
O
Serial data transfer clock signal output to the SONY bus interface (IC800)
24
N/R
I
Tape detection signal input terminal “L”: reverse side, “H”: forward side
25
ST-IND
I/O
FM stereo broadcasting detection signal input from the FM/AM tuner unit (TU100), or forced
monaural control signal output to the FM/AM tuner unit (TU100)
“L” is input in the FM stereo mode, or “L” is output in the forced monaural mode
26
KEY-ACK
I
Input of acknowledge signal for the key entry Acknowledge signal is input to accept function
and eject keys in the power off status On at input of “H”
27
NOSE-SW
I
Front panel block remove/attach detection signal input terminal
“L”: front panel is attached
28
BU-IN
I
Battery detection signal input from the SONY bus interface (IC800) and battery detect circuit
“L” is input at low voltage
29
—
I
Not used (fixed at “L”)
30
TEL-MUTE
I
Telephone muting signal input terminal At input of “H”, the signal is attenuated by –20 dB
Not used (fixed at “L”)
31
TEST-IN
I
Setting terminal for the test mode “L”: test mode, Normally: fixed at “H”
32
RAM-BU
I
Internal RAM reset detection signal input from the XC61BN3312MR (IC3)
Input terminal to check that RAM data are not destroyed due to low voltage
This checking is made within 50 msec after reset
33
RESET
I
System reset signal input from the reset signal generator (IC2) and reset switch (S2)
“L”: reset “L” is input for several 100 msec after power on, then it changes to “H”
34
SD
I
Station detector detection signal input from the FM/AM tuner unit (TU100)
Stop level for SEEK, BTM, etc. is determined SD is present at input of “H”
35
BEEP
O
Beep sound drive signal output to the power amplifier (IC500)
Used for the XR-C2300X only
36
PLL-SI
I
PLL serial data input from the FM/AM PLL (IC130)
