Icom IC-208H Service Manual page 18

(MAIN unit; IC505)–Continued
Pin Port
number name
Outputs the VCO circuit select signal.
79 VCO_SHIFT High : The VCO circuit oscillates
Outputs the VHF VCO select signal.
V_VCO High : The VHF VCO's power supply
81
83 PLLSW Outputs the PLL loop control signal.
Input port for the PLL unlock signal.
84 UNLK
High : While the loop is unlocked.
MATRIX_ Input ports for the initial matrix signals.
86–89
IN1–IN4
Outputs the PLL data signal to the PLL
90 PLLDATA
ICs (IC1, IC2).
Outputs the PLL clock signal to the
91 PLLCK
PLL ICs (IC1, IC2).
93–96 OUT1–OUT4 Output the initial matrix strobe signals
Outputs the wide/narrow FM select
WN_SEL signal.
99
Low : While selected narrow FM.
4-6-2 D/A CONVERTER IC PORT ALLOCATIONS
(MAIN UNIT; IC11)
Pin Port
number name
Output the VHF bandpass filter track-
TUNE_V1–V3
2–4
ing signals.
Outputs the UHF bandpass filter track-
5 TUNE_U
ing signal.
Outputs the receiving attenuator con-
6 ATT
trol signal.
Outputs the bandpass filter shift con-
trol signal.
7 BSHIFT
Low : While receiving 450–629.995
Outputs the VHF output power control
PCON_V
8
signal.
Outputs the UHF output power control
9 PCON_U
signal.
Outputs the 800 MHz bandpass filter
12 TUNE_8
tracking signal.
Outputs the reference frequency con-
REF_CON
13
trol signal.
Outputs the excess current detecting
18 REF_V
signal.
Description
203.95–263.945 MHz signal.
(Q6, Q8) is ON.
Description
MHz.
4-6-3 FRONT CPU PORT ALLOCATIONS
(CONTROL UNIT; IC6)
Pin Port
number name
1 BAND
3 A_LED
4 SMW
5 TONE
6 LOW
7 MONI
8 SET
24 M/CALL
25 VMHz
DIAL_A
30
31 DIAL_B
39–42 COM4–COM1
SEG1–SEG36
43–78
83 G_LED
86 PWR
88 VOL
89 SQL
4 - 10
Description
Input port for the [BAND] key.
Low : The [BAND] key is pushed.
Outputs the umber LED control signal.
High : The LED lights ON.
Input port for the [S.MW] key.
Low : The [S.MW] key is pushed.
Input port for the [TONE] key.
Low : The [TONE] key is pushed.
Input port for the [LOW] key.
Low : The [LOW] key is pushed.
Input port for the [MONI] key.
Low : The [MONI] key is pushed.
Input port for the [SET] key.
Low : The [SET] key is pushed.
Input port for the [M/CALL] key
Low : The [M/CALL] key is pushed.
Input port for the [V/MHz] key.
Low : The [V/MHz] key is pushed.
Input port for the main dial's A phase
signal.
Input port for the main dial's B phase
signal.
Output the common signals to the LCD
(DS1).
Output the segment signals to the LCD
(DS1).
Outputs the green LED control signal.
High : The LED lights ON.
Input port for the [PWR] key.
Low : The [PWR] key is pushed.
Input port for the [VOL] controller.
Input port for the [SQL] controller.