cx20493-35/app Conexant Systems, Inc., cx20493-35/app Datasheet - Page 14

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

1.4
1.4.1
1.4.2
1.4.3
1.4.3.1
1-6
CX81801-7x/8x SmartV.XX Modem in 128-Pin LQFP with CX20493 in 32-Pin LQFP Data Sheet
Technical Overview
General Description
MCU Firmware
Operating Modes
Modem operation, including dialing, call progress, telephone line interface, telephone
handset interface, optional voice/speakerphone interface, and host interface functions are
supported and controlled through the V.250, V.251, and V.253-compatible command set.
The modem hardware connects to the host via a parallel or serial interface as selected by
the PARIF input. The OEM adds a crystal circuit, DIB components, telephone line
interface, telephone handset/telephony extension interface, voice/speakerphone interface,
optional external serial EEPROM, optional external ROM/flash ROM, optional external
RAM, and other supporting discrete components as supported by the modem model
(Table 1-1) and required by the application to complete the system.
Customized modem firmware can be supported by the use of external memory in various
combinations, e.g., either external ROM/flash ROM (up to 256 KB), or external serial
EEPROM (256 to 32 KB) and external RAM (up to 128 KB). To support country profile
addition or modification, external serial EEPROM (256 to 32 KB) can be installed.
Customized code can include OEM-defined commands, i.e., identification codes (I3),
identifier string (I4), manufacturer identification (+GMI), model identification (+GMM),
and revision identification (+GMR), as well as code modification.
Parallel interface operation is selected by PARIF input high.
Serial interface operation is selected by PARIF input low.
MCU firmware performs processing of general modem control, command sets, data
modem, error correction and data compression (ECC), fax class 1, fax class 1.0,
voice/audio/TAM/speakerphone, worldwide, V.80, and serial DTE/parallel host interface
functions according to modem models (Table 1-1).
MCU firmware can be customized to include OEM-defined commands, i.e., identification
codes (I3), identifier string (I4), manufacturer identification (+GMI), model identification
(+GMM), and revision identification (+GMR), as well as code modification.
The modem firmware is provided in object code form for the OEM to program into
external ROM/flash ROM. The modem firmware may also be provided in source code
form under a source code addendum license agreement. External ROM/Flash ROM and
RAM must be installed in order to operate the modem with customized firmware.
Data/Fax Modes
Data modem modes perform complete handshake and data rate negotiations. Using
modem modulations to optimize modem configuration for line conditions, the modem
can connect at the highest data rate that the channel can support from 56 kbps down to
2400 bps with automatic fallback.
In V.92/V.90 data modem modes (V.92 models), the modem can receive data from a
digital source using a V.92-compatible central site modem at line speeds up to 56 kbps.
With PCM upstream enabled (V.92 only), data transmission supports sending data at line
Conexant
102247B