Puxing PX-777, Service Manual

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CPU PIN FUNCTION PX-777
ITEM DESCRIPTION I/O FUNCTION
1
CLK ROM I/O CLOCK AND EEPROM
2
D0 O Key scan output
3
D1 O Key scan output
4
D2 O PLL clock port/Key scan output
5
D3 O PLL data port/Key scan output
6
PLL CS O PLL CS port
7
LAMP2 O Lcd/backlight control output
8
K1 I Key scan input
9
K2 I Key scan input
10
K3 I Key scan input
11
K4 I Key scan input
12
AVDD MPU+5MV
13
RX0 O IF output control port
14
RX1 I IF input control port
15
TX1 I MIC input control port
16
TX0 O MIC output control port
17
BEEP/QT O BEEP output /CCTCS tone signal output
18
ACC MPU power filter
19
AVSS Connect to VSS
20
APC/TUNE O Automatic power &frequency automatic gain output
21
AT X O Transmitter data output select control
22
AR X I Receiver data input/audio amplifier adjustment input
23
BATT Test O Battery check /Reset
24
VOX I VOX input
25
AN SQL I Squelch signal input port
26
OSCin I Internal oscillator input
27
OSCout O Internal oscillator output
28
VSS GND
29
EN1 I Encoder data input
30
EN2 I Encoder data input
31
MONI I Monitor key input
32
Reset I CPU reset port
33
Vdd +5V power supply
34
5TC O TX power supply control output
35
LED G O LED green
36
TXD/LED R O RX232 output/ LED red
37
AFC O Audio amplifier control input
38
5CC O Power supply control output
39
P-AMP O Audio amplifier power supply control output
40
N/W/LD O Unlock detection
41
PTT/RX D I PTT key input/RX232 input
42
HT1621 CS I LCD CS port
43
LAMP1 O Backlight control output
44
DQT O DTC audio signal output