User Manual

CIRCUIT ANALYSISN
29 MHz Clock
The 29 MHz Clock consists of oscillator circuit Y2 and resistors R82 and R105. This
circuit produces the oscillator frequency of 29.4912 MHz and connects to U9A at N2
(EXTCLK).
VDDSYNC Filter
This circuit consists of inductor L1 and capacitors C50 and C57. It connects between the
3.3V supply and the VDDSYN connection through capacitor C68 to microprocessor
U9A, Pin T2 XFC.
The primary purpose of this circuit is to
Silicon Serial Number
A unique 64-bit electronic Serial Number chip U3 is used to store the board
identification number. This chip has a 1-bit serial port, which interfaces to
microprocessor U9A through an I/O port. In addition, four bits of hardware identification
are made available to U9A through I/O ports. The Hardware ID is changed based by
selectively populating a bank of resistors.
KAPWR Switch
The KAPWR switch consist of Schottky diodes D30 and D31 and battery BT1. This
switch applies 3.3V supply or 3.3V battery to U9A, Pin
KAPWR
8-Bit Bus Transceiver
This circuit consists of 8-Bit Bus Transceiver U19 and resistor network RN15. The 8-Bit
Bus connects to the microprocessor through 8-Bit Bus Transceiver U19. The output
enable OE for the transcreiver is controlled by ANDing all 8-bit chip selects together
inside EPLD U27.
MICTOR Logic Analyzer Connectors
These connections consists of J3, J5 and J6.
6.3.5Modem Daughter Board Connector
The Modem Daughter Board connector circuits for the Controller Board is shown on
Schematic Diagram WD-CB101069V1, Sheet 10 and include:
• QUICC Connector (J1) • I/O Connector (J2)
6.5.1 QUIC Connector (J1)
The QUICC (J9) connector contains the microprocessor interface (Refer to the Modem
Daughter Board Section).
38 MM101271V1 R1A