Part of the D/120JCT-LS board’s telephone inter face
includes an on-hook audio path that detects Caller ID
information. Depending on the level of service offered
by the local telephone provider, Caller ID can include
the date, time, caller’s telephone number, and the
name of the person calling (in some enhanced Caller
ID environments). The on-hook audio path can also
detect touchtones while the line is on-hook. This capa-
bility lets developers use the D/120JCT-LS board
behind PBXs that require on-hook touchtone detection
for signaling.
When the onboard call processing resources are used,
the network signals are extracted and passed to the
onboard control processor, which can change channel
status and communicate channel events to the applica-
tion via a shared RAM and the host PC PCI bus.
The Motorola 56303 Onyx DSP processes the digitized
voice data based on Spring Ware firmware loaded in
code/data RAM. Each Motorola 56303 Onyx DSP per-
forms the following signal analysis and operations.
On the incoming data:
■Applies automatic gain control (AGC) to compensate
for variations in the level of the incoming audio signal
■Applies an Adaptive Differential Pulse Code
Modulation (ADPCM), Pulse Code Modulation (PCM)
algorithm, G.726 32 Kb/s coding or GSM, to com-
press the digitized voice and save disk storage
space
■Detects the presence of tones (DTMF, MF, or an
application-defined, single or dual tone)
■Detects silence to determine whether the line is quiet
and the caller is not responding
For outbound data:
■Expands stored, compressed audio data for play-
back
■Adjusts the volume and rate of speed of playback
upon application or user request
■Generates tones — DTMF, MF, or any application-
defined general-purpose tone
The dual-processor combination also performs the fol-
lowing outbound dialing and call progress monitoring:
■Transmits an off-hook signal to the telephone network
■Dials out (places an outbound call)
■Monitors and reports results: line busy or congested;
operator intercept; ring, no answer; or if the call is
answered, whether answered by a person, an
answering machine, a facsimile machine or a modem
When recording speech, the Motorola 56303 Onyx DSP
can use digitizing rates from 24 to 64 Kb/s as selected
by the application for the best speech quality and most
efficient storage. The digitizing rate is selected on a
channel-by- channel basis and can be changed each
time a record or play function is initiated. The DSP-
processed speech is transmitted by the control proces-
sor to the host PC for disk storage. The D/120JCT-LS
board can record incoming signals with the telephony
interface in either the high-impedance on-hook state or
the normal off-hook state. When replaying a stored file,
the processor retrieves the voice information from the
host PC and passes it to the Motorola 56303 Onyx
DSP, which conver ts the file into digitized voice. The
DSP sends the digitized voice responses to the codec,
which is controlled by three QSLAC chips. The codec
converts the digitized voice into analog voice and
sends the voice response to the caller via the tele-
phone line interface.
Although this product is capable of recording incoming
signals in an on-hook state, applications such as call
logging should use the D/160SC-LS-HiZ (ISA form
factor), which is specifically designed for analog high-
impedance recording.
When the system is initialized, Spring Ware firmware is
downloaded from the host PC to the board. Spring
Ware controls all board operations and gives the board
all of its intelligence and enables easy feature
enhancements and upgrades.
The onboard control processor controls all operations
of the D/120JCT-LS board via a local bus and interprets
and executes commands from the host PC. This
processor handles real-time events, manages data flow
to the host PC to provide faster system response time,
reduces PC host processing demands, processes
DTMF and telephony signaling before passing them to
the application, and frees the Motorola 56303 Onyx
DSPs to perfor m signal processing. Communication
between the processor and the host PC is via shared
RAM that acts as an input/output buffer and thus
increases the efficiency of disk file transfers. This RAM
interfaces to the host PC via the PCI bus. All operations
are interrupt-driven to meet the demands of real-time
systems. The Board Locator Technology circuit oper-
ates in conjunction with a rotary switch that eliminates
the need to set confusing jumpers or DIP switches.
5
Datasheet
Intel®Dialogic®D/120JCT-LS Combined Media Board