Icom IC-A14 Service Manual - page 11
4 - 5
LINE NAME
DESCRIPTION
IN/
OUT
STATUS
CONDITION
PTT
Ext. [PTT] input.
IN
High
While transmitting. (=[PTT] is pushed.)
UNLK
PLL unlock signal from the PLL IC (IC29).
IN
Low
While PLL is unlocked.
SCK
Clock signal to the DAC (IC17).
OUT
–
–
SDATA
Serial data to the DAC (IC17).
OUT
–
–
RSSI
RSSI voltage from the IF IC (IC1).
IN
–
–
RFDETV
TX power monitor.
(The DC voltage which is in proportional to the TX power.)
IN
–
–
THERMC
Internal temperature moniter.
(The DC voltage which is divided by thermistor (R701) and R702.)
IN
–
–
VOL_IN
[VOL] dial position detect.
(The DC voltage which is divided by R824.)
IN
–
–
VIN
Remaining battery capacity monitor.
(The voltage of "HV" line divided by R194 and R19.)
IN
–
–
DETO
1050 Hz tone (for weather alert) detect.
IN
–
–
DA2STB
Strobe signal to the DAC (IC17).
OUT
Low
–
EDATA
Serial data to the EEPROM (IC25).
I /O
High
–
ECK
Clock signal to the EEPROM (IC25).
OUT
High
–
POW
TX power setting voltage to the APC AMP (PA: IC27).
OUT
–
–
PCON
Control signal to the +3.6V regulator (Q89).
OUT
High
+3.6V regulator is activated.
(=+3.6V and +5V lines are ON.)
HOUT
Battery type detect.
(The voltage of +5V line which divided by R838 and R839.)
IN
High
Li-ion battery pack is attached.
HSW
Battery type detect circuit control.
OUT
High
Detect circuit is activated.
KR0–KR4
Key matrix.
IN
Low
While the key is pushed.
PSTB
Strobe signal to the PLL IC (IC29).
OUT
High
–
PDATA
Serial data to the PLL IC (IC29).
OUT
High
–
PCK
Clock signal to the PLL IC (IC29).
OUT
High
–
TXC
TXV regulator (Q7, 8) control signal.
OUT
High
TXV regulator is activated.
LIGHTC
Backlight (DS2, 3) driver (Q75, 76) control signal.
OUT
High
Backlight is ON.
LIGHT
[LIGHT] key input.
IN
Low
While the key is pushed.
JACKDET
Ext. speaker conection detect.
IN
High
Ext.speaker is connected.
EXTREGC
EXT-MIC regulator (Q25, 26) control signal.
OUT
High
While an ext. microphone is connected.
(
While the VOX circuit is activated; "Low."
)
KS0–KS3
Strobe signals for key matrix.
OUT
Low
All the time "Low."
INI
Initial matrix return signal.
IN
Low
Any key is pushed.
EMBI
Int. microphone control signal to the MIC controller (Q79).
OUT
High
Int. microphone is enable.
(While in VOX mode;"Low.")
INTPTT
[PTT] key input.
IN
Low
While the key is pushed.
(=While transmitting)
BEEP
Beep sounds (AF square waves).
OUT
–
–
AGCOFF
AGC SW (Q85) control signal.
OUT
High
AGC function is disable.
NOISE
Noise level for noise squelch. (pulse-type signal)
IN
High
(Upper edge of the pulse)
SPCON
Speaker select signal to the AF power AMP (IC31).
(Switching to internal or External speaker)
OUT
Low
Ext. speaker is selected.
VOX
VOX control signal from the IC21.
(A portion of MIC signals which is amplifi d by IC21.)
IN
A/D
TX=Voltage is high
RX=Voltage is low
AFC
AF power AMP controller (Q36, 82) control signal.
OUT
High
AF power AMP is activated.
(=Squelch is open.)
ALCC
ALC AMP controller (Q52) control signal.
OUT
High
ALC AMP is activated.
(=The ALC function is activated.)
R5C
R5S line regulator (Q20, 90) control signal.
OUT
Low
While receiving
ANLC
ANL SW (Q21) control signal.
OUT
High
ANL circuit is activated.
(=The ANL function is activated.)
WXC
AF/FM SW (IC2) control signal.
OUT
High
While receiving an WX channel.
SHIFT
VCO SW (Q57) control signal.
OUT
High
While transmitting. (=TX VCO is
activated.)
DETMUTE
AF/FM SW (IC2) control signal.
OUT
High
While RX AF is mute.
4-4 PORT ALLOCATIONS
• CPU (IC26)