Microprogrammed Control based System Design and FPGA based Implementation of a Telephone Dial Tester

Abstract

Accurate dialing is indispensable for proper communication through a Public Switched Telephone Network (PSTN). In pulse dialing scheme of PSTN, pulses are transmitted as an identification of the destination station. An error in the transmitted pulses may lead to a false connection or no connection can be established with erroneous pulses. In this paper, a totally different design methodology based on the microprogrammed control unit has been adopted for testing the dialing scheme. This will introduce a new degree of flexibility in the up-gradation of the system. The entire tested design of Telephone Dial Tester has been implemented in a highly miniaturized Field programmable gate array (FPGA). The design can be very easily upgraded to include tone dialing scheme as well on account of microprogrammed control and FPGA based implementation.