A job dispatcher-collector made of FPGA's for a centralized Voice Server

Abstract

It is the purpose of this paper to describe a specific application made of XILINX XC4000 series Field Programmable Gate Arrays (FPGA's).

The application takes advantage of a feature of this RAM based device where logic is implemented under the form of an array of small look-up tables which may be as well used as an array of small RAMS. The paper shows how this array of RAMs is well suited to do the function that dispatches and collects, over a bunch of Digital Signal Processors or DSP's, Digitized Voice Packets that need to be compressed (decompressed) before (after) transmission on a Tele Processing line to realize a Voice Server function that saves a significant amount of the transport medium bandwidth.

The paper tends to demonstrate that the availability of x1 organized independent internal RAM devices permits to simply carry out the function, at the nominal speed, in a couple of FPGA s while the equivalent function would only be achievable in a standard gate array at the expense of the use of many Flip Flops.