Motorola APX 1000 Detailed Service Manual page 734

3-30
3.2.3 Clock Sources
The main board and keypad 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
TRIDENT
26 MHz
Clock Frequency
Source
Y6501 24.576 MHz
Y6502 32.768 kHz
Y6601 12 MHz
U6302 96 MHz
U6101 32.768 kHz
Y701 16.8 MHz
(RF
board)
Chapter 6.
GPS
Figure 3-19. Controller Clock Architecture
Table 3-5. Controller Clock Distribution
Type Description
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 OMAP Boot-Up clock & GPS/
Bluetooth digital clock
Crystal RF Frequency Synthesizer
Oscillator IC (Trident) TCXO
Theory of Operation
SQUARING
16.8 MHz
32.768 kHz
12 MHz
CPLD
32.768 kHz
24.576 MHz
Main Board
Clock Recipient
U6501, U6101
U6501
U6302
U6301
U6302 & U2401
(Keypad Board)
U6302
: Controller
DDR
96 MHz
OMAP
MAKO
Suggested Probe
Points
R6574
C6541
C6601
TP6307 & TP6308
R6114 (GPS/BT) &
R6115 (OMAP)
R6218