Table 3-5. Controller Clock Distribution; Figure 3-21. Controller Clock Architecture - Motorola APX 3000 Detailed Service Manual

Theory of Operation
: Controller
3.2.3 Clock Sources
The main board contains multiple crystal clock sources. These sources are active upon power-up.
The controller receives a 16.8 MHz sine wave from the RF section, which is shaped into square
wave and fed to the OMAP timer input. Screen shots and test points for these clock signals are
shown in Chapter
TRIDENT
26 MHz
Clock Frequency
Source
Y6501 24.576 MHz
Y6502 32.768 kHz
Y6601 12 MHz
U6302 96 MHz
U6101 4.096 MHz
U6101 32.768 kHz
Y701 16.8 MHz
6.
GPS
4.096 MHz
MACE

Figure 3-21. Controller Clock Architecture

Table 3-5. Controller Clock Distribution

Type
Crystal MAKO 24 MHz & tapped into
Oscillator CPLD
Crystal MAKO RTC
Oscillator
Crystal OMAP CPU Clock
Oscillator
OMAP GPIO DDR Clocks
(Complementary signals)
CPLD GPIO MACE Clock
CPLD GPIO OMAP Boot-Up clock & GPS/
Bluetooth digital clock
Crystal RF Frequency Synthesizer
Oscillator IC (Trident) TCXO
SQUARING
16.8 MHz
32.768 kHz
CPLD
32.768 kHz
24.576 MHz
Main Board
Description
U6501, U6101
U6501
U6302
U6301
U2510
U6302 & U2401
U6302
96 MHz
OMAP
12 MHz
MAKO
Clock Recipient Suggested Probe
R6574
C6541
C6601
TP6307 & TP6308
R6113
R6114 (GPS/BT) &
R6115 (OMAP)
R6218
3-29
DDR
Points