Icom IC-F33GT Service Manual page 14

4-6-2 CPU (MAIN unit; IC22)
Pin Port
number name
13, 15, CENC0– Output the CTCSS/DTCS signals.
16 CENC2
Outputs the reference oscillator cor-
29 REF recting voltage. The voltage is applied
to the buffer amplifi er (IC24, pin 3)
Outputs strobe signals to the PLL IC
30 PLST
(IC21, pin 16).
Outputs the FM/PM modulation
34 PMFM switching signal to the FM/PM switch
(IC13, pin 5).
I/O port for the serial data signals
35 MDIO from/to the base band IC (IC14,
pin 11).
Outputs clock signal for the base
36 MSCK
band IC (IC14, pin 13).
Outputs serial data control signal to
37 MDIR
the base band IC (IC14, pin 14).
Input port for transmitting MSK clock
38 MTCK signal from the base band IC (IC14,
pin 9).
Outputs MSK data for transmitting to
39 MTDT
the base band IC (IC14, pin 10).
Input port for the receiving MSK de-
40 MRDF tection signal from the base band IC
(IC14, pin 12).
Outputs strobe signals to the D/A
41 DAST
convertor (IC12, pin 6).
43 SENC Output single tone encoder signal.
44 BEEP Outputs beep audio signals.
Input por t for single tone decode
45 SDEC signal from the base band IC (IC14,
pin 21).
Input port for CTCSS/DTCS signal
46 CDEC
from the amplifi er (IC19, pin 1).
Input port for the detect signal for
48 BATV
connecting battery pack's voltage.
49 LVIN Input port for the PLL lock voltage.
Input port for the S-meter signal from
50 RSSI
the FM IF IC (IC9, pin 12).
Input port for the transceiver's internal
51 TEMP
temperature detecting signal.
Outputs shift signal for reference os-
69 CSFT
cillator's frequency.
Outputs audio control signal.
70 AFON Low: While outputs audio signals
Description
from the speaker.
Pin Port
Number name
74 PTT
75 NOIS
76 SO
78 SCK
79 CLI
80 CLO
82 ESDA
84 MUTE
85 ESCL
86 S5C
87 T5C
88 R5C
89 TMUT
4 - 6
Description
Input port for the PTT switch detec-
tion signal.
Low: While the PTT switch is
pushed.
Input port for the noise signal from
the FM IF IC (IC9, pin 13).
Outputs serial data to the PLL IC
(IC21, pin 15) and D/A conver tor
(IC12, pin 8).
Outputs serial clock signal to the PLL
IC (IC21 pin 14), D/A convertor (IC12,
pin 7), etc.
Input port for the cloning data signal.
Outputs the cloning data signal.
I/O port for data signals from/to the
EEPROM (IC10, pin 5).
Outputs AF control signal .
Low: While Squelch ON.
Outputs clock signal to the EEPROM
(IC10, pin 6).
Outputs the S5 regulator (Q26–Q28)
control signal.
Low: While the S5 regulator out-
puts 5 V voltage.
Outputs the T5 regulator (Q24) con-
trol signal.
Low: While transmitting.
Outputs the R5 regulator (Q25) con-
trol signal.
Low: While receiving.
Outputs the transmitting mute switch
control signal to the mute switch
(Q 501).
High: While muting.