Telephone exchange having permanent memory for operating instructions

Claim 1

A branch exchange for a telephony system comprising a plurality of interconnectable equipments each forming a source of audio signals, temporary memory means for recording equipment addresses and status information relating to each recurring time slot within the system, a read only memory having recorded therein a multiplicity of binary coded words forming instructions for the automatic establishment and disestablishment of time division connections within the system, each instruction including one or more words and all words of each instruction occupying sequential address positions within the memory, a source of clock pulses occurring at predetermined intervals, address register means responsive to said clock pulses for accessing sequential instructions within said memory, data register means for receiving the output of the memory, decoder means for identifying instructions which require more than one clock cycle for execution, clock pulse gating means for blocking clock pulses from reaching the address register, and search frame counter means responsive to the decoder means for activating the clock pulse gatE means for an interval equal in duration to one complete frame of time slots.

Claim 6

A method of providing coded operating instructions to control the establishment and disestablishment of time division audio connections between sources of audio signals in an automatic branch exchange for a telephony system comprising: maintaining in a temporary memory a constantly updated record of currently established connections and the addresses of audio signal sources involved in those connections: periodically and continuously supplying clock pulses to an address register and reading permanently recorded instructions from a permanent memory in response to all clock pulses that are not blocked; decoding a portion of the first word of each instruction to determine the number of words in that instruction; setting an instruction register to temporarily record therein the successive words of the instruction; decoding the instruction to determine whether the address register should read the next instruction sequentially or whether it should branch to a designated permanent memory address and controlling the address register accordingly; and further decoding the instruction to determine whether it requires a search of information available within the temporary memory relating to established connections; and blocking clock pulses in response to the decoding of a search instruction and searching the contents of the temporary memory while said clock pulses are blocked.

Claim 7

A method of providing coded operating instructions to control the establishment and disestablishment of time division audio connections between sources of audio signals in an automatic branch exchange for a telephony system comprising: maintaining in a temporary memory a constantly updated record of currently established connections and the addresses of audio signal sources involved in those connections: periodically and continuously supplying clock pulses to an address register and reading permanently recorded instructions from a permanent memory in response to all clock pulses that are not blocked; decoding a portion of the first word of each instruction to determine the number of words in that instruction; setting an instruction register to temporarily record therein the successive words of the instruction; decoding the instruction to determine whether the address register should read the next instruction sequentially or whether it should branch to a designated permanent memory address and controlling the address register accordingly; and further decoding the instruction to determine whether it requires a search of information available within the temporary memory relating to established connections; and blocking clock pulses in response to the decoding of a search instruction and searching the contents of the temporary memory while said clock pulses are blocked.