Port Allocations - Icom IC-A14 Service Manual

4-4 PORT ALLOCATIONS

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