Patent References 3315039 Time shared TCMF and MF decoder Microprocessor control complex for a telecommunication switching system Time division switching system control arrangement Distributed control for digital switching system Patent #: 4317962 InventorsAssigneeApplicationNo. 06/377574 filed on 05/13/1982US Classes:379/386, Signal receiver (e.g., tone decoder)370/526, Digital tone detection379/283, Dual tone multifrequency (DTMF) receiver379/284With processorExaminersPrimary: Brown, Thomas W.Attorney, Agent or FirmInternational ClassesH04Q 1/457 (20060101)H04Q 1/32 (20060101) H04Q 1/30 (20060101) AbstractA dual tone multifrequency and dial pulse receiver that receives 8000 digital data words per second, each of the data words including eight PCM bits representing the analog signal transmitted from a subscriber set and also including a line status bit indicating the DC status of the line. The receiver includes a time-shared processor which processes the PCM bits of 4000 words per second to detect tone-pairs and which also processes the line status bit of 4000 words per second to detect valid dial pulse sequences. The time-shared processor stores one of a first plurality of code words in a register when a tone-pair is detected and stores one of a second plurality of code words in the register when a valid dial pulse sequence is detected. Advantageously, the receiver can detect either dual tone multifrequency or dial pulse signaling from a subscriber even though the type of signaling to be used by the subscriber is not known a priori. | |