Digital Control Unit - Kenwood TM-321A Service Manual

-321A
CIRCUIT DESCRIPTION
Digital control unit
@
General
The control unit consists of
a microprocessor, input
keys,
peripheral
circuits,
and
a
display. The single micro-
processor (1C3) controls all transceiver
functions. The
pin
assignments
of
the microprocessor are
listed on the
Table
4.
@
Keys
and
rotary encoder input circuits
Fig.
7 shows the input
circuit for
the keys and rotary
encoder. Data from the front
panel
keys, microphone
keys,
and rotary encoder are applied
directly to
the
microprocessor.
MIC UP
Mic
SS
Mic
DOWN:
Fig.
7
Key
and
rotary encoder input circuits
Terminal Terminal
Name 1/0
Logic
Function
Name HO
Logic
Function
P41
35 TI1
P40 36 TIO Not
used.
37
P23
P53
P52
Digital output of D-A
conv.
Sauelch control during
remote
P22
P51
control.
39 P21 P50
Shift
register strobe.
RESET
Reset input.
40
PTOO
Beep
oscillator output.
X2
Microphone DOWN switch input/
X1
4.194304MHz
crystal oscillator.
41
P03/SI
L/-
serial data input.
10 P63
Microphone
PTT
switch input/
Not
used.
42
P02/SO 1/0
L/-
11
P62
serial
data input.
Microphone UP switch input/
12 P61
CTCSS
shift
register reset
43
P01/SCK
L/-
serial data
input.
13
P60
44 INT4 Backup detect input.
45 P123
SHIFT
switch input.
14
P73
LCD
driver data. 46
P122
M.IN switch input.
15
P72
LCD
driver clock. 47 P121 VFO/M select switch input.
16 P71
LCD
driver enable. 48
Pi20
REV
switch input.
7
P70
Not
used.
49 P133
Frequency
step select switch input
50 P132
18 P83
SCAN
switch input.
19 P82
CTCSS
switch input.
51
P131
20 P8t
Directional input.
21
P80 52 P130
TONE
switch input.
22 P93
Not
used. 53
P143 Puil-down pin.
23 P92
PLL
and shift
register
clock. P142
24
P91
55 P141
PLL
and
shift register data.
Not
used.
25 P90
PLL
enable.
56 P140
26 Vss
GND
terminal
(OV).
57
NC
27 P13
BUSY
input.
58
VDD Power supply pin (5V).
28
INT2
59
P33 GND
terminal (OV).
Encoder input.
29
INT1
60
P32
Tone detect input (when
CTCSS
Remote connection detect input
is
on
30 INTO
(only
when connected).
61 P31
CTCSS
IC data
31
PTH03
Not used.
62 P30
CTCSS
IC clock.
32
PTH02 63 P43
DAC
digital data output.
33 PTH01
RF
meter analog input.
64
P42
34 PTHOO S meter analog input.
1
2
3
38
4
5
6
7
8
54
Table 4 uPD75106G-508-1B
pin assignments
(Control unit
1C3)
-321A
CIRCUIT DESCRIPTION
Digital control unit
@
General
The control unit consists of
a microprocessor, input
keys,
peripheral
circuits,
and
a
display. The single micro-
processor (1C3) controls all transceiver
functions. The
pin
assignments
of
the microprocessor are
listed on the
Table
4.
@
Keys
and
rotary encoder input circuits
Fig.
7 shows the input
circuit for
the keys and rotary
encoder. Data from the front
panel
keys, microphone
keys,
and rotary encoder are applied
directly to
the
microprocessor.
MIC UP
Mic
SS
Mic
DOWN:
Fig.
7
Key
and
rotary encoder input circuits
Terminal Terminal
Name 1/0
Logic
Function
Name HO
Logic
Function
P41
35 TI1
P40 36 TIO Not
used.
37
P23
P53
P52
Digital output of D-A
conv.
Sauelch control during
remote
P22
P51
control.
39 P21 P50
Shift
register strobe.
RESET
Reset input.
40
PTOO
Beep
oscillator output.
X2
Microphone DOWN switch input/
X1
4.194304MHz
crystal oscillator.
41
P03/SI
L/-
serial data input.
10 P63
Microphone
PTT
switch input/
Not
used.
42
P02/SO 1/0
L/-
11
P62
serial
data input.
Microphone UP switch input/
12 P61
CTCSS
shift
register reset
43
P01/SCK
L/-
serial data
input.
13
P60
44 INT4 Backup detect input.
45 P123
SHIFT
switch input.
14
P73
LCD
driver data. 46
P122
M.IN switch input.
15
P72
LCD
driver clock. 47 P121 VFO/M select switch input.
16 P71
LCD
driver enable. 48
Pi20
REV
switch input.
7
P70
Not
used.
49 P133
Frequency
step select switch input
50 P132
18 P83
SCAN
switch input.
19 P82
CTCSS
switch input.
51
P131
20 P8t
Directional input.
21
P80 52 P130
TONE
switch input.
22 P93
Not
used. 53
P143 Puil-down pin.
23 P92
PLL
and shift
register
clock. P142
24
P91
55 P141
PLL
and
shift register data.
Not
used.
25 P90
PLL
enable.
56 P140
26 Vss
GND
terminal
(OV).
57
NC
27 P13
BUSY
input.
58
VDD Power supply pin (5V).
28
INT2
59
P33 GND
terminal (OV).
Encoder input.
29
INT1
60
P32
Tone detect input (when
CTCSS
Remote connection detect input
is
on
30 INTO
(only
when connected).
61 P31
CTCSS
IC data
31
PTH03
Not used.
62 P30
CTCSS
IC clock.
32
PTH02 63 P43
DAC
digital data output.
33 PTH01
RF
meter analog input.
64
P42
34 PTHOO S meter analog input.
1
2
3
38
4
5
6
7
8
54
Table 4 uPD75106G-508-1B
pin assignments
(Control unit
1C3)