Telecom
Interfaces
The EmPack’s foundation board can be ordered with
two full-duplex T1 or E1 interfaces, complete with over-voltage protection
for direct connection to outside lines.
Software is provided to direct selected
timeslots to the host computer or to any other EmPack resource(s).
In the case where the T1s or E1s have different clock sources,
on-board circuitry synchs to the fastest clock. Slips on the TDM bus
of slower lines are marked by an invalidation bit, causing it to be
automatically ignored by the device(s) receiving the data.
This feature also applies to configurations with multiple
foundation boards.
T1, by default, implies RJ45 connectors on the front panel and 100 ohm
impedance.
E1 is available with Trompeter CJ70, BNC or RJ45 connectors which is
specified in the
ordering information.
E1 impedances of 75, 100, and 120 ohm are jumper selectable.
Stereo audio interface
A stereo CODEC (Analog Devices AD1845) is included on the foundation
board when the EmPack is order with either a T1 or E1 interface.
The sampling rate of this 16-bit sigma-delta converter is user software
programmable from 4kHz to 48kHz in 1Hz increments. Its anti-aliasing
and reconstruction filters automatically track the sampling rate.
The gain and attenuation is programmable to 22.5dB in 1.5dB steps.
A mating cable is available to connect to an audio source.
RS232 interfaces
Two RS232 ports share the audio’s 15-pin connector on the front
panel. These ports connect to the serial ports of both Hitachi
processors for debugging embedded code or for user control.
Status LEDs
Four LED’s mounted onto the foundation board are visible
through the EmPack’s front panel. Two indicate T1/E1 activity
(green, one for each line), one indicates SCSI bus activity (green),
and one indicates error conditions (red).
Backend Hitachi Processor
The EmPack’s back end Hitachi processor is responsible
for the SCSI, SCSA and TDM buses as well as the parallel bus used
to communicate with the mezzanine boards. It communicates with the
front end processor through 8k bytes of dual-ported SRAM. The SH7032
is a 32-bit SuperH RISC processor.
Frontend Hitachi Processor
The EmPack’s front end Hitachi processor is responsible
for the T1/E1 interface and the stereo audio codec. The SH7032 is a
32-bit SuperH RISC processor.
Global DRAM
The EmPack foundation board has a minimum of 2MB of DRAM which
is used by the backend Hitachi processor to transfer data to/from the
host across the SCSI bus.
More DRAM may be added in 2MB increments up to 8MB.
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