Midland 70-1341, Service Manual, Page: 44 / 68

CIRCUIT DESCRIPTION
70-1341/1344/1441/1444
Table 5-1 — IC901 Pinouts
Pin No. Pin Name I/O Function Label Logic & Function
1 P62 P-ON RESET
2 P61 +B SW
3 P60 DTONE SW
4 P77 RSSI
5 P76 I PTT Low = TX
6 P75 I HANG UP Low = Hang Up
7 P74 CH DET
8 P73 CH CONT
9 SCLK2 CH CLK
10 S OUT2 CH-SD/UP
11 S IN2 CH-RD/DN
12 DA2 TX STONE
13 DA1 TX STONE
14 CNTR1 TONE DET
15 CNTR0 DTONE DET
16 P53 I NSQ Noise Squelch Status (High = Receive)
17 INT3 RDF
18 INT2 TCLK
19 TOUT O BEEP Beep Tone Output
20 P47 I/O RTS Programmer Interface
21 P46 I/O CTS Programmer Interface
22 TXD1 I/O RD Programmer Interface
23 RXD1 I/O SD Programmer Interface
24 INT1
25 INT0
26 CNVSS
—
GND Ground
27 RESET I — — Low = Microprocessor Reset
28 P41 I/O D I/O
29 P40 TX DATA
30 X IN I — — 8 MHz Crystal Oscillator
31 X OUT O — — 8 MHz Crystal Oscillator
32 VSS
—
GND Ground
33 P27 BEEP CONT
34 P26 DTMF MUTE
35 P25 SYN STB
36 P24 SYN CLK
37 P23 SYN DATA
38 P22 ROM CLK2
39 P21 ROM CLK1
40 P20 ROM DATA
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