cx20493-35/app Conexant Systems, Inc., cx20493-35/app Datasheet - Page 17

• Manufacturer Part Number: cx20493-35/app
• Description: With Cx20493 Smartdaa?
• Manufacturer: Conexant Systems, Inc.

1.4.3.5
1.4.4
1.5
1.5.1
102247B
CX81801-7x/8x SmartV.XX Modem in 128-Pin LQFP with CX20493 in 32-Pin LQFP Data Sheet
Reference Designs
Hardware Description
CX81801 Modem Device
Speakerphone Mode (S Models)
S models include additional telephone handset, external microphone, and external
speaker interfaces which support voice and full-duplex speakerphone (FDSP) operation.
Hands-free full-duplex telephone operation is supported in Speakerphone Mode under
host control. Speakerphone Mode features an advanced proprietary speakerphone
algorithm which supports full-duplex voice conversation with acoustic, line, and handset
echo cancellation. Parameters are constantly adjusted to maintain stability with automatic
fallback from full-duplex to pseudo-duplex operation. The speakerphone algorithm
allows position independent placement of microphone and speaker. The host can
separately control volume, muting, and AGC in microphone and speaker channels.
A data/fax/TAM/speakerphone reference design for an external modem is available to
minimize application design time, reduce development cost, and accelerate market entry.
A design package is available in electronic form. This package includes schematics, bill
of materials (BOM), vendor part list (VPL), and complete documentation.
SmartDAA technology eliminates the need for a costly analog transformer, relays, and
opto-isolators that are typically used in discrete DAA implementations. The
programmable SmartDAA architecture simplifies product implementation in worldwide
markets by eliminating the need for country-specific components.
The CX81801 Modem, packaged in a 128-pin LQFP, includes a Microcontroller (MCU),
a Modem Data Pump (MDP), 256 KB internal ROM, 32 KB internal RAM, and
SmartDAA interface functions.
The CX81801 Modem connects to host via a parallel host (PARIF = high) or a logical
V.24 (EIA/TIA-232-E) serial DTE interface (PARIF = low).
The CX81801 Modem performs the command processing and host interface functions.
The crystal frequency is 28.224 MHz ± 50 ppm.
The CX81801 Modem optionally connects to an external OEM-supplied serial EEPROM
over a dedicated 2-line serial interface. The capacity of the EEPROM can be 256 bytes up
to 32 KB. The EEPROM can hold information such as firmware configuration
customization, and country code parameters.
The CX81801 Modem performs telephone line signal modulation/demodulation in a
hardware digital signal processor (DSP) which reduces computational load on the host
processor.
The SmartDAA interface communicates with, and supplies power and clock to, the LSD
through the DIB.
The CX81801 optionally connects to external OEM-supplied ROM/flash ROM and RAM
over a non-multiplexed 19-bit address bus and 8-bit data bus.
Conexant
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