SX Microcontroler based
Modems
Useing Virtual Peripherals, software modules that replace a traditional hardware
peripheral, these "Virtual" modems take advantage of the SX architecture’s
high performance and deterministic nature to produce same results as the
hardware peripheral with much greater flexibility.
Bell-103 300Baud FSK Modem This application demonstrates the generation
of FSK tones to simulate a 300 Baud modem
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Source 1.08 04/16/99 This simple
program encodes an outgoing bell103 signal. This program only creates the
answer frequencies, since it cannot dial out to originate.
To use this program, connect the SX-DTMF-DEMO board to a phone line and to
a PC. The communications settings are 300,N,8,1. Now, from a remote BELL103
modem, simply dial the modem's number. When you hear the line ringing on
the dialing modem, press a key in the comm window of the SX-modem-board.
This should force the modem board off-hook and cause it to send out an answer
tone for 3 seconds. Once the answer tone is sent, the modem board will begin
modulating the state of the RS-232 pin onto the carrier. If the terminal
program is set up correctly, you will be able to receive the sent characters
on the remote modem.
Bell-202 1200Baud FSK Modem This application combines
Bell-202
1200Baud FSK I/O,
DTMF output and 1200bps UART. Also
includes AT command interface. Designed to be compliant with the
Bell-202 specification and Scenix
SX Modem evaluation board. Virtual Periperals used in this integration include:
DTMF (Dual Tone Multiple Frequency
Signalling) generation for dialing, FSK (Frequency Shift Keying) generation
for transmitting data, FSK detection for receiving data,
UART (Universal Asynchronous
Receiver/Transmitter) for RS-232 communications with a PC, 16-bit timer for
delay routines/flashing LED.
Also:
Bell-212 2400Baud V.23 PFSK Modem Telephony Solution-V.23 Originate
Mode Reference Design. Ubicom' modem reference design provides a complete
system solution for a V.23 modem in originate mode. It's main purpose is
to provide a user the capability to quickly embed the Ubicom solution into
applications that require the use of a low-speed modem. The Ubicom solution
consists of: SX28AC communication controller with V.23 modem Peripheral software
modules loaded into the on-chip flash/EEPROM; an RS232 jack and line interface
circuit for data-side connection; a line driver (DAA) and RJ-11 jack for
telephone-side connection; an operational amplifier (op-amp)/resistor-based
adjustable hybrid circuit to accommodate various line impedance. The V.23
modem is compliant with the CCITT V.23 standard and it has been tested in
accordance with the FCC (Federal Communications Commission) standards.
Also:
Questions: