Motorola CP150TM User Manual
Page 57
6880309N62-C
June, 2005
VHF Troubleshooting Tables: Troubleshooting Table for Board and IC Signals
6-15
U451
ASFIC_CMP
14
GCB1 general purpose output
0
15
GCB0 general purpose output
3.00
BW select (25 kHz mode)
16
Squelch channel activity output
0
To U401-84
17
Squelch detect digital output
0
To U401-83
18
PL/low speed data I/O
1.50
19
High speed data I/O
3.00
20
Chip select
3.23
From U401-2
21
Serial clock input
0
22
Serial data input
3.23
23
Ground for clock synthesizer
GND
24
Loop filter cap for clock syn
0.74
25
PLCAP2 for LS integrator
1.17
26
Not used
0
27
Vdd for clock synthesizer
3.00
28
Clock synthesizer output
1.70
29
1200 Hz ref for MDC decode
3.00
30
GNDDO
GND
31
Ground for digital circuits
GND
32
Vdd for analog switches
4.96
33
Vdd for digital circuits
3.00
34
16.8 MHz master clock input
1.54
35
GCB3 general purpose output
3.00
Internal MIC enable
36
TX audio return from option
0
37
GCB4 general purpose output
0
38
GCB5 general purpose output
0
39
RX audio send to option
1.48
40
Modulation output
1.50
To U201-10
41
RX audio out to power amp
1.51
42
Flat TX audio return from option
0.20
43
RX audio return to option
1.50
44
Flat TX audio send to option
1.50
45
Vdd for audio path I/O filters
3.00
46
Mic audio input
1.50
47
Ground for audio path I/O filters
GND
48
Ext mic audio input (not used)
0
Table 6-4. Troubleshooting Table for Board and IC Signals (Continued)
IC Designator
Pin
Pin Function
DC Voltage
Comments (Condition)