4) Terminal Function of Microprocessor
Port No. I/O Logic PinName Description
1 O SEG19 LCDSegment19 Output
2 O SEG20 LCDSegment20 Output
3 O SEG21 LCDSegment21 Output
4 O SEG22 LCDSegment22 Output
5 O SEG23 LCDSegment23 Output
6 I GND AnalogGround 0V
7 I Vref Reference Voltage Input 5V
8 I Vcc CPU Power Supply hnput 5V
9 O 1750_ ToneBurstOutput
10 O Clock BEEP BeepToneOutput
11 I Active Low MUP Channel Up Input (Microphone Control)
12 I Active Low MDN Channel Down Input (Microphone Control)
13 I NoUse EID
14 O Active Low SQL Squelch Control (L: Audio is off.)
15 O ActiveHigh MUT Microphone Mute (H: Mic Amp is off.)
16 I Active Low REl RotaryEncoder Input
17 O Clock TO3 ToneOutput
18 O Clock TO2 ToneOutput
19 O Clock TO1 ToneOutput
20 O Clock TO0 ToneOutput
21 I ActiveHigh XWR EEPROM Write Status External Input
22 I Active Low RE2 RotaryEncoder Input
23 O Active Low BPO Band Plan Detection Input (Common)
24 I Active Low TID Tone Unit Detection Input
25 I Active Low BU Back Up Signal Detection input
26 I GND Ground
27 l Active Low RST ResetInput
28 I Xin Crystal Oscillator Terminal (3.58MHz)
29 O Xout Crystal Oscillator Terminal (3.58MHz)
30 I GND Ground
31 I Active Low TDO CTCSS Tone Detection Output
32 O Active Hig
DTD For Trunking
33 O NoUse
34 I Active Low DD4 Band Plan 4 (V/U Selection)
35 I Active Low DD3 Band Plan 3 (445/435 Selection)
36 I Active Low DD2 Band Plan 2 (5k/12.5k Selection)
37 I Active Low DD1 Band Plan 1
38 I Active Low DD0 Band Plan 0
39 O Clock SCL Clock Output for EEPROM
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