![background image](http://html.mh-extra.com/html/icom/ic-f6220d/ic-f6220d_service-manual_612654012.webp)
5 - 4
5-5 PORT ALLOCATIONS
• CPU (FRONT UNIT: IC51)
BALL
No.
LINE
NAME
DESCRIPTION
I/O
A1
KR1
[P1]
input.
I
A5
RXC
Power supply switching control.
H= During receive or stand-by.
O
A7
TDAT Serial data to the DSP (IC2007).
O
A15
PWON
Power supply switching control.
H= The transceiver's power is ON.
O
B1
KR3
[P3]
input.
I
B2
KR0
[P0]
input.
I
B12
NOIS
Noise level detect.
H= Squelch close
I
B13
EPTT
External PTT input.
H= An external PTT is pushed.
I
B14
PGIO4 External I/O port.
I/O
B15
AFON
AF mute SW control.
H= During the squelch circuit is opened.
O
C3
KR2
[P2]
input.
I
C5
TXC
Power supply switching control.
H= While transmitting.
O
C8
ESDA EEPROM (IC52) serial data.
I/O
C12
POSW
[ ]
input.
I
C14
ADS
1st IF filters (FI4 and FI5) switching
control.
L= During digital mode.
O
C15
NWC
R e c e i ve m o d e ( n a r r ow / m i d / w i d e )
switching.
L= During narrow mode.
O
D6
DSCK DSP (IC2007) clock.
O
D8
ESCL EEPROM (IC52) clock.
O
D13
DPDN
DSP (IC2007) power control.
H= DSP is inactivated
O
D14
DRES
DSP (IC2007) reset.
L= Reset
O
D15
CSFT
Clock frequency shift.
H= Clock frequency is shifted.
O
E13
CRES CPU reset.
I
H1
SIDE1
[ ]
key input.
L= Pushed
I
H2
SIDE2
[ ]
key input.
L= Pushed
I
J1
IPTT
Microphone [PTT] input.
L= Pushed.
I
K3
LIGT1
LCD dimmer control.
H= Dimmer OFF.
O
L1, L2
MCG0,
MCG1
MIC gain control.
O
L3
LIGT2
Backlight control.
H= Backlight ON.
O
L4
HANG Microphone hang up detection.
I
L14
SSO
Common serial data.
O
L15
SCK
Common clock.
O
M1
TMUT
Transmission mute.
L= TX inhibit.
O
M8
BEEP Beep audio. (Square waves)
O
M14
DAST
D/A converter (IC1006) strobe.
H= Load enable.
O
N2
LINH
LCD driver (IC6) chip enable.
H= Enable.
O
N4
UNLK
PLL (IC8) unlock detect.
L= Unlocked.
I
N12
BATV Power supply voltage sensing.
I
BALL
No.
LINE
NAME
DESCRIPTION
I/O
N14
RDAT DSP (IC2007) serial data.
O
N15
IGSW
Ignition SW detect.
L=Ignition detected.
I
P1
LCK
LCD driver (IC6) clock.
O
P2
LCS
LCD driver (IC6) chip select.
O
P4
PLSW
PLL lock up time control.
L= Fast lock up
O
P10
TEMP Temperature sensing voltage.
I
P11
RSSI
RSSI sensing voltage.
I
P12
AFVI
[VOLUME CONTROL]
input.
I
R1
LSO
LCD driver (IC6) serial data.
O
R4
PLST PLL strobe.
O
R10
LVIN
Lock voltage input.
I