Motorola EP450

HKLN4216A November 24, 2003
VHF Troubleshooting Tables: Troubleshooting Table for Board and IC Signals 5-13
U401
Microprocessor
82 PA3_IC4_OC5_OC1 3.00
83 PA4_OC4_OC1 0 Squelch detect input
84 PA5_OC3_OC1 0 Channel activity input
85 PA6_OC2_OC1 0
86 PA7_PA1_OC1 0
87 VSSR GND
88 VDDR 3.23
89 ECLK (NU) 1.60
90 EXTAL 1.70 Clock from U451-28
91 XTAL 1.40 Not used
92 VDDSYN 0
93 XFC (NU) 0
94 RESET 3.20 From U320
95 LVOUT 0
96 IRQ 3.20
97 PD0_RXD 3.23
98 PD1_TXD 1.9
99 PD2_MISO 0
100 PD3_MOSI 3.23
U402
EEPROM
1 Chip select 3.23 From U401-3
2 Serial data out 0
3 Write protect 3.23
4 Vss GND
5 Serial data in 3.23
6 Serial clock 0
7Hold 3.23
8 Vcc 3.23
U404
Flash ROM
1 A11 3.06
2 A9 3.08
3A8 3.05
4 A13 0.13
5 A14 0.31
6 NC 3.17
7 EN_WE 3.21 From U401-4
8 Vcc 3.23
9 RESET 3.20
Table 5-4. Troubleshooting Table for Board and IC Signals (Continued)
IC Designator Pin Pin Function DC Voltage Comments (Condition)