Icom IC-706MKIIG Service Manual page 14

3-4-4 MAIN CPU PORT ALLOCATIONS
(MAIN unit; IC2001)
Pin Port
number name
Input port for the external paddle
13 DASK (DASH).
Low : During key down
Input port for the external paddle
DOTK (DOT) or straight key.
14
Low : During key down
Input port for the PLL unlock signal
from the DDS IC (PLL unit; IC101) and
15 UNLK
PLL IC (PLL unit; IC461).
Low : while PLL unlock
Input port for transmit control signal
16 TKEY from the optional AT-180/AH-4 anten-
na tuners.
Input port for the optional antenna
tuner connection detection.
17 TCON
High : When the optional antenna
Outputs a squelch control signal for
18 SQSS
the external unit.
Input port for the [POWER] switch.
19 PWK Low : When the [POWER] switch is
Outputs the switching relay (PA unit;
20 POWS RL591) control signal.
High : While power is ON.
Outputs start signal for the optional
ATST
21
AT-180 antenna tuner.
Output port
22 BEEP
Outputs start signal for the optional
23 AHST
AH-4
Outputs squelch mute control signal,
applied to the AF mute switch (MAIN
24 AFMS
board; Q772).
Low : While squelch is closed.
Input port for the CTCSS decode sig-
30 CTCV
nal from the low-pass filter (IC811C).
Input port from the [RTTY] or [MIC]
31 SNDL connector.
High : While transmitting.
32 VOXL Input port for the VOX voltage.
33 AVXL Input port for the anti-VOX voltage.
ALC level input port for the ALC meter
34 ALCV
indication.
37 TONE Outputs subaudible tone signals.
Input port for the optional UT-102
(Voice synthesizer unit) activation sig-
39 SPBK
nal.
High : During speech synthesis.
Description
tuner is connected.
pushed.
: Beep audio signals while
receiving.
: CW side tone signals while
transmitting.
(MAIN unit; IC2001)–Continued
Pin Port
number name
40 ETON
MSST
41
42 MDT
43 MCK
BSTB
44
45 DSST
46 ASTB
PBST
48
49–51 CON2–
CON0
52 PDST
53 PMST
54 PDT
55 PCK
AFGS
61
62 NBS
63 ATTS
71 FMST
74 SNDS
75 KDS
78 LTXD
79 LRXD
3 - 9
Description
Outputs 1750 Hz European tone sig-
nal.
Outputs a strobe signal for the option-
al UT-102 (Voice synthesizer unit).
Outputs serial data for the I/O
expanders, optional AT-180/UT-102.
Outputs a clock signal for the I/O
expanders, optional AT-180/ UT-102.
Outputs a strobe signal for the I/O
expander ICs (IC2231, IC2232).
Outputs a strobe signal for the I/O
expander ICs (IC2221, IC2222).
Outputs a strobe signal for the D/A
converter IC (IC2201).
Outputs a strobe signal for the BFO
DDS IC (PLL unit; IC901).
Output mode control signals for the 1st
LO DDS IC (PLL unit; IC101).
Outputs a strobe signal for the 1st LO
DDS IC (PLL unit; IC101).
Outputs a strobe signal for the 1st LO
PLL IC (PLL unit; IC461).
Outputs serial data for the DDS ICs
(PLL unit; IC101, IC901) and PLL IC
(PLL unit; IC461).
Outputs a clock signal for the DDS ICs
(PLL unit; IC101, IC901) and PLL IC
(PLL unit; IC461).
Outputs AGC rate select signal
Low : When AGC fast is selected.
Outputs the NB switch (Q635) control
slignal.
High : When the [NB] is turned ON,
except FM/WFM modes.
Outputs the attenuator circuit control
slignal.
High : When the [ATT] is turned ON.
Outputs a strobe signal for the TX FM
PLL IC (IC1011).
Input port for transmit/receive switch-
ing signals for the [ACC] connector.
Low : While transmitting.
Outputs a CW keying signal or RTTY
TX signal.
Output port for CI-V bus line.
Input port for CI-V bus line.