Service manual

FO-IS125N
5 – 8
9) CX95110 (IC1000) Terminal description
Pin Name Pin No. Pin I/O I/O Type Signal Description
Crystal/Clock Signals
XTALI/CLKIN 31 I OSC Crystal/Oscillator In. The modem must be connected to
an external crystal/oscillator circuit consisting of a 28.224
MHz crystal/oscillator.
Label Crystal Oscillator
XTALI/CLKIN XTALI CLKIN
XTALO 32 O OSC Crystal Out. The modem must be connected to an external
crystal circuit consisting of a 28.224 MHz crystal. Do not
connect when using an oscillator.
Label Crystal Oscillator
XTALO/NC XTALO NC
Host Control Signals
RESETn 10 I GPH Reset. RESETn low holds the modem in the reset state.
RESETn going high releases the modem from the reset
state and initiates normal operation using power turn-on
(default) values. If RESETn is asserted during normal oper-
ation, RESETn must be held low for at least 3 µs. During
power-on, RESETn must be held low for at least 10 ms
after VDDO (+3.3 V) is within operating limits. The modem
is ready to be accessed by the host 320 ms after bit 2 of
register $2E is set to a 1.
IRQ 8 O GP Interrupt Request. Interrupt generated by modem DSP
sources. The polarity is programmable. When it is active
low, the signal can be connected with other active low,
open-drain IRQ sources to form a single interrupt request in
a wire-OR configuration. In that configuration, an external
pull-up resistor to +3.3V is required on the line, and should
be located near the receiver of IRQ.
CSn 1 I GPH Chip Select. The active low CSn input selects and enables
the HSD for serial data transfer between the HSD and the
host over the SPI interface.
Serial Peripheral Interface (SPI)
SDI 2 O GPH Serial Data Input. Output data from modem to host con-
troller (SPI master).
SDO 3 I GPH Serial Data Output. Input data to modem from host con-
troller (SPI master).
SCK 4 I GPH Serial Data Clock. SPI input clock.
GPIO Signals
GPIO0 11 I/O GPH General Purpose I/O 0. Hysteresis input with a bus holder.
GPIO1 12 I/O GPH General Purpose I/O 1. Hysteresis input with a bus holder.
GPIO2 13 I/O GPH General Purpose I/O 2. Hysteresis input with a bus holder.
GPIO3 18 I/O GPH General Purpose I/O 3. Hysteresis input with a bus holder.
GPIO4 19 I/O GPH General Purpose I/O 4. Hysteresis input with a bus holder.
Ring Indicator Signal
RIn 9 O GP Ring Indicator. The RIn output follows the ringing signal
coming out of the DSP’s ring qualification block with a low
level (0 V) during the ON time, and a high level (+3.3 V)
during the OFF time.
Speaker Interface Signals
SDAA_PWM 22 O GP Speaker Output. Analog or digital speaker output signal for
line monitoring function. An external speaker driver is
needed. If no used, tie to ground through a 75 kΩ resistor.
SmartDAA Interface Signals
SDAA_RCREF 30 I - SSD RC Oscillator Reference. Connect to VDDO through
a 240 kΩ resistor.