The dual-processor combination also performs the follow-

ing outbound dialing and call progress monitoring:

— 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 DSP can use different digi-

tizing rates from 24 Kb/s to 64 Kb/s as selected by the

application for the best speech quality and most efficient

storage. The digitizing rate can be selected on a channel-

by-channel basis and can be changed each time a record

or play function is initiated. Outbound processing is the

reverse of inbound processing. The DSP processed

speech is transmitted by the control microprocessor to

the host PC for disk storage. When replaying a stored file,

the microprocessor receives the voice information from

the host PC and passes it to the DSP which converts the

file into digitized voice. The DSP sends digitized voice to

the CODEC to be converted into analog voice and then

to the line interface for transmission to the telephone net-

work.

The on-board microprocessor controls all operations of

the DIALOG/4 board via a local bus and interprets and

executes commands from the host PC. This

microprocessor

system response time

them to the application

Communications between this microprocessor and the

host PC is via the shared RAM that acts as an input/out-

put buffer, increasing the efficiency of disk file transfers.

This RAM interfaces to the host PC via the XT/AT bus. All

operations are interrupt-driven to meet the demands of

real-time systems. All DIALOG/4 boards installed in the

PC share the same interrupt line. When the system is ini-

tialized, Spring Ware firmware to control all board opera-

tions is downloaded from the host PC to the on-board

code/data RAM and DSP RAM. This downloadable

firmware gives the board all of its intelligence and enables

easy feature enhancement and upgrades.

4

Datasheet