Kenwood KDC-8021, Service Manual

Page: 7 / 27

KDC-8021/M9021/X859
7
MICROCOMPUTER'S TERMINAL DESCRIPTION
Pin Name I/O Purpose Processing Operation
Processing During Processing During
Non-Operation STBY
1 MC-DATA I/O
DATA line to Panel
uCOM.
Hi-Z Hi-Z
2 MC-CLK O CLK line to Panel uCOM.
Panel attached: "H".
Detached: "Hi-Z".
H
3 PLL-DATA I/O DATA I/O to/from F/E. Hi-Z Hi-Z
4 PLL-CLK I/O CLK I/O to/from F/E. Hi-Z Hi-Z
5 AM+B I/O
AM power supply
terminal.
During AM operation: "H". Hi-Z Hi-Z
During FM operation: "H".
6 FM+B I/O FM power supply terminal. With RDS and RBDS Hi-Z Hi-Z
only, last FM: "H".
7 CH-CON O CH control output. ON:H OFF: L L L
Normally "H". In recovery
8 CH-RST O CH reset output.
after system RST,
remains H for 400 ms
L L
then goes L"
9 Evdd -
Positive power supply
terminal.
10 Evss - GND terminal.
During FM seek and
Last FM with RDS
11 AFS O
Time constant switching
AM search: L.
and RBDS: "H".
upon noise detection.
During reception; H.
Without RDS and
L
RBDS: "L".
12 BEEP O Beep output terminal. L L
Since there is no
13 REMO I
Wired remote input
wired remote control,
terminal.
connected to GND.
14 N.C O Output Open. Not used. L
15 N.C O Output Open. Not used. L
16 IC2-SDA I/O
IC2, IC5 and CD
mechanism DATA line.
Hi-Z Hi-Z
17 IC2-SCL I/O
IC2, IC5 and CD
mechanism CLOCK line.
Hi-Z Hi-Z
"L" when M MUTE R is
L (during CD playback).
"H" (other sources
18 PRE-MUTE R O PREOUT(Rch)MUTE "L" during momentary
than CD)
H
power down. "H" only in
2-zone operation.
"L" when M MUTE R is
L (during CD playback).
19 PRE-MUTE L O PREOUT(Lch)MUTE "L" during momentary
H (other sources
H
power down. "H" only in
than CD)
2-zone operation.
20 N.C O Output Open. Not used. L
21 TEST - Test pin. Normal: "L". During
22 N.C(SVR) O
power OFF: "H" in 5 sec. "H" ("L" in 5 sec.
Power OFF: H after Power OFF).
23 P-MUTE O Power IC MUTE terminal.
Power OFF: L All OFF: "L ("H" in 5 sec.
"L". Tel muting: "L"
H
after P-ON OFF).
POWER IC ON: H
24 P-STBY O Power IC STBY terminal. POWER IC OFF : L L L
ALL OFF: H
ON: Open. OFF: "L".
25 MUTE O Muting terminal. Time constant: 0.48 ms L
Open ("H" in 5 sec.
(with both ON/OFF)
after P-ON OFF).
SYSTEM MICROCOMPUTER uPD703033AGF- *** -3BA (X25)