Port Allocations - Icom IC-F4261DT Service Manual

4-5 PORT ALLOCATIONS

• CPU (MAIN-A/B/C UNIT: IC35)
Pin Port
No. Name
Bandwidth switches (Q27–Q29, D8, D16)
A3 NWC1 control.
"High"=While operating in the wide mode.
B3 DUSE CTCSS/DTCS switch (Q12) control.
B11 CENC0 CTCSS/DTCS tone encode signals.
B12 NOIS Noise signal from the IF IC (IC15).
Strobe signal to the DTMF decode IC (MAIN-A/
B13 DDST
B/C UNIT: IC10).
C6 ESCL Serial clock to the EEPROM (IC36).
Serial data to the expander (FRONT UNIT:
C8 FSDA
IC702 and IC703).
C11 CENC1 CTCSS/DTCS tone encode signals.
Power switch (VR UNIT: R502).
C12 POSW
" "
Low =While the power is ON.
Serial clock to the baseband IC (MAIN-A/B/C
C13 MTCK
UNIT: IC4).
C14 DDSD Serial data to the DTMF decode IC (IC10).
Bandwidth switches (Q18, D3, D4) control.
D4 NWC2 "High"= While operating in the narrow or digital
mode.
D6 ESDA Serial data to the EEPROM (IC36).
Serial clock to the expanders (FRONT UNIT:
D8 FSCL
IC702 and IC703).
D11 CENC2 CTCSS/DTCS tone encode signals.
D12 DDAC Serial clock to the DTMF decode IC (IC10).
Serial clock to the baseband IC (MAIN-A/B/C
D13 MSCK
UNIT: IC4).
CPU clock frequency shift control.
D15 CSFT
"High"=The clock frequency is shifted.
CPU reset signal from the reset IC (IC34).
E13 RES
"High"=CPU is reset.
K1–
CBI0−2 [ROTARY SELECTOR] (VR UNIT: S501).
K3
L1 EMER [Emer] (VR UNIT: S501).
[Side1] (S3).
L2 SIDE1
" Low " =Pushed.
L3 CBI3 [ROTARY SELECTOR] (VR UNIT: S501).
[Side2] (S2).
L4 SIDE2
" Low " =Pushed.
[Side3] (S1).
M1 SIDE3
" "
Low =Pushed.
TX indicator (FRONT UNIT: DS710) control.
M3 TLED
"High"=While transmitting.
S5V line control.
M4 S5C
" "
Low =While in the power save mode.
M5 PMFM PM/FM switch (IC13) control.
AF mute switch (IC8) control.
M7 RMUTO
"Low"=Mute.
M8 SENC Single tone encode signal.
M11 BATV Battery voltage.
[PTT] (S4).
M14 IPTT
" "
Low =Pushed.
RX indicator (FRONT UNIT: DS710) control.
N1 RLED
"High"=While receiving a signal.
PLL IC (IC14) unlock detect.
N2 UNLK
"Low"=Unlocked.
VCC line control.
N4 PWON
" "
Low =While the power is ON.
T5V line control .
N5 T5C
" "
Low = While transmitting.
N8 BEEP Beep sound (Square wave).
N10 SDEC Decoded 2/5 tone and DTMF signals.
N12 RSSI RSSI voltage from the IF IC (IC15).
Serial clock to the PLL IC (IC14) and D/A
P1 SCK
converter (IC9).
Description
Pin Port
No. Name
Serial data to the PLL IC (IC14) and D/A
P2 SSO
I/O
converter (IC9).
P3 DAST Strobe signal to the D/A converter (IC9).
Outputs mode (Digital/Analog) switching
O
P4 DASW control.
"High"=While operating in the analog mode.
O
R5V line control.
O
P5 R5C
"
Low
I
Outputs emphasis characteristic switching
P6 EMPH
O control.
P12 LVIN Lock voltage.
O
Transmit mute switch (RF UNIT: Q604) control.
R1 TMUT
O "High"=Mute.
R2 DSDA Serial data to the D/A converter (IC33).
O
R4 PLST PLL strobe signal to the PLL IC (IC14).
I
Serial data to the baseband IC (MAIN-A/B/C
R3 MTDT
UNIT: IC4).
O
R10 CDEC CTCSS/DTCS signals.
O
• D/A CONVERTER (MAIN-A/B/C UNIT: IC33)
O
Pin Port
No. Name
I/O
Tuning voltage to the tuned BPF (
1 T1
O
L29, C308, C309, C320, C322, C323,
• While receiving
O
Tuning voltage to the tuned BPF (
O
L23, L25, C273, C278, C287, C291
2 T2
O • While transmitting
TX power setting voltage to the APC AMP (RF
UNIT: IC601).
O
Oscillating frequency adjustment voltage to the TX
3 TLVA
VCO (
I
Outputs oscillating frequency adjust voltage to the
4 RLVA
RX VCO-A/B (
I
I
• EXPAND IC (FRONT UNIT: IC702)
I
Pin Port
I
No. Name
AF power amplifi er (IC705 and IC706) control.
I
4 AFON
"High"=Activated.
LCD backlight control.
I
5 LIGH
"High"=While the backlight lights.
Internal or external speaker select.
O
6 SPCON
"Low"=While the internal speaker is used.
Internal or external microphone select.
O
7 MCON
"Low"=While the internal microphone is used.
O
O
O
I
I
O
I
O
O
O
I
I
O
4 - 4
Description
"
= While receiving.
Description
D21,D24, L27,
Q32, D9, D12, D13)
.
Q30, D10, D14/Q31, D11, D15)
Description
I/O
O
O
O
O
O
I
O
O
O
O
I
).
D17, D18,
).
.