Furuno FS-1503, Service Manual

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2-7
2. CPU Input/output Control Signals
Table 2-2 CPU Function List
U6: I/O Port IN/OUT Function (Signal name) Description
P30 OUT T/R TX/RX selection, TX: H
P31 OUT MUTE MUTE ON: H
P32 OUT EXC ON TX/RX Exciter ON/OFF, TX:H
P33 OUT PA ON PA selection, TX: H
P34 OUT TX KEYED BK output, TX: H
P35 OUT BK ON ANT BK signal, TX: H
P36 OUT VS EN Not used
P37 OUT THROU Ant. Coupler "through" signal, H: ON/OFF
P40 OUT DATA Shift register serial data
P41 OUT CLK Shift register clock
P42 OUT PLL1 ENB 1st osc. PLL IC shift register strobe signal
P43 OUT PLL3 ENB 3rd osc. PLL IC shift register strobe signal
P44 OUT DDS LOAD DDS IC shift register strobe signal
P45 OUT ST SYN SYN shift register strobe signal
P46 OUT ST TX/RX TX/RX shift register strobe signal
P47 OUT ST PA/FIL TX FIL shift register strobe signal
P17 OUT TUNE Ant. Coupler tune signal
P24 OUT FAN Fan ON/OFF signal, ON: H
P76 OUT TONE Two-tone alarm and key beep output
P77 OUT DUMMY Dummy in ant. coupler ON/OFF, ON: H
P92 OUT ALC REFF ALC reference voltage, propertion to power data
P93 OUT RF GAIN RF GAIN voltage
P94 OUT DA3 Not used
P97 OUT RUN CPU RUN signal, square wave
P80 IN S S-meter analog input
P81 IN IA IA-meter analog input
P82 IN RF RF-meter analog input
P83 IN TEMP Over temperature detector analog input
P84 IN IC IC meter analog input, not used
P85 IN VC VC meter analog input, not used
P86 IN RF GAIN VR RF GAIN Voltage
P87 IN CHK EXC TX/RX output check signal analog input