si2493 Silicon Laboratories, si2493 Datasheet - Page 18

• Manufacturer Part Number: si2493
• Description: V.92 Isomodem With Global Daa
• Manufacturer: Silicon Laboratories

Si2493
4. Functional Description
The Si2493 ISOmodem
modem
arrangement (DAA) that provides a programmable line
interface to meet global telephone line requirements.
Available in two small packages, this solution includes a
DSP data pump, modem controller, on-chip RAM and
ROM, codec, DAA, analog output, and 27 MHz clock
input.
The Si2493 accepts standard modem AT commands and
provides connect rates up to 56/33.6/14.4/2.4 kbps full-
duplex over the Public Switched Telephone Network
(PSTN). The Si2493 features a complete set of modem
protocols including all ITU-T standard formats up to V.92.
To provide the most flexibility, the Si2493 ISOmodem
system-side device is offered in either a 24-pin TSSOP or
a 16-pin SOIC package. The 16-pin version is footprint-
compatible
recommended for most applications. The 16-pin version
does not support the parallel, EEPROM or voice codec
interface. If these features are required, customers
should use the 24-pin version.
The ISOmodem provides numerous additional features
for embedded modem applications. The modem includes
full type I and type II caller ID detection and decoding for
global standards. Call progress monitoring is supported
through standard result codes. The modem is also
programmable to meet global settings. Because the
Si2493 ISOmodem integrates the DAA, analog features,
such as parallel phone detect, overcurrent detection, and
global PTT compliance with a single design, are included.
18
CLKOUT
EECLK
RESET
D0-D7
EESD
EECS
MISO
MOSI
SCLK
RXD
DCD
TXD
CTS
RTS
ESC
WR
CS
RD
INT
A0
SS
RI
Figure 8. Functional Block Diagram
chipset
EEPROM
Interface
Interface
Interface
with
Interface
Parallel
UART
SPI
XTI
Clocking
PLL
the
with
XTO
Program Bus
Data Bus
Si2401
®
integrated
is a complete embedded
ROM
RAM
ISOmodem
Interface
DAA
direct
C1
C2
AOUT
and
access
To Phone
Line
Rev. 1.3
is
This device is ideal for embedded modem applications
due to its small board space, low power consumption,
and global compliance. The Si2493 solution includes a
silicon DAA using Silicon Laboratories’ proprietary third-
generation DAA technology. This highly-integrated DAA
can
specifications for ac termination, dc termination, ringer
impedance, and ringer threshold. In addition, the Si2493
has been designed to meet the most stringent worldwide
requirements
immunity, surge immunity, and safety requirements.
The Si2493 allows for rapid integration into existing
modem applications by providing a serial interface that
can directly communicate to either a microcontroller via a
UART interface or a PC via an RS-232 port. This
interface allows for PC evaluation of the modem
immediately upon powerup via the AT commands using
standard terminal software.
4.1. Host Interface
The Si2493 interfaces to the host processor through
either an asynchronous serial interface, a synchronous
Serial Peripheral Interface (SPI), or a parallel interface.
The default is asynchronous serial communication.
Selection of either SPI or parallel interface is done on
power-up with reset strapping. Please refer to “AN93:
ISOmodem
details.
4.1.1. Asynchronous Serial Interface
The
communication with data terminal equipment (DTE) at
rates up to 307.2 kbps with the standard serial UART
format. Upon powerup, the UART baud rate is
automatically detected using the autobaud feature.
4.1.2. Serial Peripheral Interface (SPI)
The serial peripheral interface (SPI) provides a flexible,
full-duplex synchronous serial bus for host processor
and Si2493 ISOmodem communication. When the
Si2493 is powered up with SPI mode enabled the
modem becomes an SPI slave, and the pins are
configured to SS (slave select input, active low), MOSI
(serial data input to modem), MISO (serial data output
from modem) and SCLK (serial data clock input). Each
SPI operation consists of a control-and-address byte
and a data byte.
4.1.3. Parallel Interface (24-Pin Version Only)
The Si2493 can also communicate via a parallel
interface when using the 24-pin version. The parallel
interface is an 8-bit data bus with a single bit address to
memory mapped registers.
be
Si2493
programmed
®
Chipset Family Designer's Guide” for
for
supports
out-of-band
to
meet
asynchronous
energy,
worldwide
billing-tone
serial
PTT