Voiceband data set

• US 4,419,756 A
• Filed: 06/05/1980
• Issued: 12/06/1983
• Est. Priority Date: 06/05/1980
• Status: Expired

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Dennis, Thomas M., Cheng-Quispe, Enrique, Fulcomer, Emanuel J. Jr., Malek, George, Tong, Shih Y.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Chin, Stephen
• Application Number:
  US06/156,869
• Time in Patent Office: 1,279 Days
• Field of Search: 375/7, 375/8, 375/9, 371/22, 179/2 DP, 370/85, 370/89.90, 364/900 MS File, 364/200 MS File
• US Class Current: 379/93.32
• CPC Class Codes: H04L 27/00 Modulated-carrier systems
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence

Abstract

A full duplex, synchronous data set (10) includes primary signal processing circuitry which generates a modulated transmit data signal in response to serial data from a terminal interface (17). The modulated data signal is transmitted over a primary channel of a transmit line (11). The primary signal processing circuitry also receives modulated data signals from a primary channel of a receive line (12) and recovers therefrom a serial bit stream for presentation to the interface. The operating parameters of the primary signal processing circuitry are specified by a primary controller (30) over a plurality of buses (PA, PC, PD). The primary controller includes a microprocessor (310) and associated peripherals (315, 320, 325, 330, 335). The data set also includes secondary signal processing circuitry (40) which transmits and receives diagnostic and control information over respective secondary channels of the transmit line and receive lines. The secondary signal processing circuitry is controlled by a secondary controller (50) over a plurality of buses (SA, SC, SD). The secondary controller also includes a microprocessor (510) and associated peripherals (515, 520, 525, 530, 535). The primary and secondary controllers communicate with each other via a bus interface (60).

Claims

1. A data set for processing data applied to said data set to generate transmit telephone voiceband data signals representing said data, said data set characterized by

signal processing means which includes a plurality of addressable registers,

a bus common to said registers, and

controller means for addressing said registers and for writing into each register via said bus at least a first associated information signal, the values of the information signals in said registers specifying the manner in which said data are to be processed,

said signal processing means further including circuit means distinct from said controller means for processing said data in accordance with said information signal values to generate said transmit telephone voiceband data signals, and means for applying said transmit telephone voiceband data signals to a telephone line.

4. The invention of claims 1 or 2 wherein said controller means includes background means operative for repetitively monitoring predetermined signals within said data set and for performing predetermined actions as a function of the values of said predetermined signals.

5. The invention of claim 4 wherein said signal processing means further includes means for generating an interrupt signal in response to at least a first predetermined signal event within said signal processing means and wherein said controller means further includes interrupt service means for suspending the operation of said background means in response to the generation of said interrupt signal and for writing predetermined information signals into the associated ones of said registers, the values of said predetermined information signals being associated with said signal event.

6. The invention of claim 5 wherein said background means includes means for identifying said predetermined information signal values.

7. The invention of claim 4 wherein said background means includes means (901) for checking the integrity of the circuitry of said data set and for providing an indication if a fault in said circuitry is detected.

8. The invention of claims 1, 2 or 3 wherein at least ones of said information signals specify operating modes for said signal processing means.

9. The invention of claims 1, 2 or 3 wherein at least ones of said information signals specify operating parameter values for said signal processing means.

10. The invention of claims 1, 2 or 3 wherein at least ones of said information signals specify signal processing formats for said signal processing means.

11. The invention of claims 1, 2 or 3 wherein said circuit means includes

means for performing at least a portion of said processing in response to a set of program instructions stored within said circuit means, and

means adapted to receive said program instructions from said controller means prior to initiation of said processing.

2. A data set for processing received telephone voiceband data signals applied to said data set to recover far-end data characterized by

signal processing means which includes a plurality of addressable registers,

a bus common to said registers, and

controller means for addressing said registers and for writing into each register via said bus at least a first associated information signal, the values of the information signals in said registers specifying the manner in which said received telephone voiceband data signals are to be processed,

said signal processing means further including circuit means distinct from said controller means for processing said received telephone voiceband data signals in accordance with said information signal values to recover said far-end data.

3. A data set for processing data applied to said data set to generate transmit telephone voiceband data signals representing said data, and for processing received telephone voiceband data signals applied to said data set to recover far-end data characterized by

signal processing means which includes a first plurality of addressable registers and a second plurality of addressable registers

a bus common to said first and second pluralities of addressable registers, and

controller means for addressing said registers and for writing into each register via said bus at least a first associated information signal, the values of the information signals in said first plurality registers specifying the manner in which said data are to be processed and the values of the information signals in said second plurality registers specifying the manner in which said received telephone voiceband data signals are to be processed,

said signal processing means further including circuit means distinct from said controller means for processing said data in accordance with the information signal values in said first plurality registers to generate said transmit telephone voiceband data signals and for processing said received telephone voiceband data signals in accordance with the information signal values in said second plurality registers to recover said far-end data, and means for applying said transmit telephone voiceband data signals to a telephone line.

12. A data set comprising

signal processing means including means for encoding user-provided data in accordance with at least a specified one of a plurality of predetermined encoding formats, and means for applying to a voiceband telephone channel a transmit data signal generated in response to the encoded data in accordance with a specified one of a plurality of predetermined modulation formats useable over voiceband telephone channels, said signal processing means further including a plurality of registers,

a bus common to said registers, and

a stored-program-controlled processor distinct from said signal processing means and including means for writing information signals into ones of said registers via said bus, ones of said information signals specifying to said signal processing means said encoding and modulation formats.

13. The invention of claim 12 wherein

said data set further comprises a request-to-send lead, the signal on which has a first value if the user desires to provide data to said signal processing means and a second value otherwise, and means for generating an interrupt signal when the signal on said request-to-send lead switches to said first value,

said signal processing means is controllable in response to other predetermined information signals written into others of said registers to generate a predetermined start-up signal and to apply said start-up signal to said channel ahead of said transmit data signal,

said processor further includes background means operative for detecting faults in at least predetermined portions of the circuitry comprising said data set and means for performing predetermined actions when such faults are detected, and

said processor further includes interrupt service means operative in response to said interrupt signal for suspending the operation of said background means and for controlling said signal processing means to generate said start-up signal by writing said other predetermined information signals into said others of said registers.

14. The invention of claims 12 or 13 wherein ones of said predetermined encoding formats are scrambling formats and others of said predetermined encoding formats are differential encoding formats.

15. The invention of claim 14 wherein at least one of said predetermined modulation formats is a phase-shift-keying format and at least another is a quadrature-amplitude-modulation format.

16. The invention of claim 15 wherein others of the information signals written into said ones of said registers specify bit and baud rates.

19. The invention of claims 12, 13, 17 or 18 wherein others of the information signals written into said ones of said registers specify bit and baud rates.

17. A data set comprising

signal processing means including means for demodulating a passband data signal received by said data set from a voiceband telephone channel, said passband data signal representing encoded data, and for decoding the demodulated signal in accordance with at least a specified one of a plurality of predetermined decoding formats, said signal processing means further including a plurality of registers,

a bus common to said registers, and

a stored-program-controlled processor distinct from said signal processing means and including means for writing information signals into ones of said registers via said bus, ones of said information signals specifying to said signal processing means said decoding formats.

18. The invention of claim 17 wherein

said data set further comprises means for generating an interrupt signal in response to reception of said data signal,

said signal processing means is controllable in response to other predetermined information signals written into others of said registers to process an initial portion of said data signal to initiate the operation of said demodulating and decoding means,

said processor further includes background means operative for detecting faults in at least predetermined portions of the circuitry comprising said data set and means for performing predetermined actions when such faults are detected, and

said processor further includes interrupt service means operative in response to said interrupt signal for suspending the operation of said background means and for controlling said signal processing means to process said initial portion by writing said other predetermined information signals into said others of said registers.

20. The invention of claims 17 or 18 wherein ones of said predetermined decoding formats are descrambling formats and others of said predetermined decoding formats are differential decoding formats.

21. The invention of claim 20 wherein others of the information signals written into said ones of said registers specify bit and baud rates.

22. A data set which includes

transmitter means operative for generating in response to near-end data a data signal representing said near-end data and adapted for transmission over a voiceband telephone channel, said transmitter means including a plurality of individual circuits each of which has at least two selectable operating modes, and further including means for appying said data signal to a voiceband telephone channel,

26. The invention of claims 22, 23 or 24, wherein said background means further includes means for monitoring user-controlled signals the values of which are indicative of respective actions to be executed by said data set and means responsive to each said value for initiating the execution of the respective action.

32. The invention of claims 22, 23 or 24 wherein the operating modes of at least one of said circuits are "on" and "off".

33. The invention of claims 22, 23 or 24 wherein at least one of said circuits distributes timing signals to others of said circuits and has as at least ones of its operating modes the generation of said timing signals in response to respective timing sources.

34. The invention of claims 22 or 24 wherein at least one of said circuits obtains said near-end data and has as ones of its operating modes the obtaining of said near-end data from respective data sources.

35. The invention of claim 33 wherein one of said data sources provides as said near-end data at least a first predetermined start-up data signal.

23. initialization means operative for placing at least ones of said circuits in respective initial ones of said operating modes,

background means operative subsequent to the operation of said initialization means, said background means including means for monitoring predetermined signals within said data set and operative in response to a determination from the values of ones of the monitored signals that a fault exists in said data set for providing a fault indication,

means for generating an interrupt signal in response to an indication from a source external to said data set that operation of said transmitter means is desired, and

interrupt service means operative in response to said interrupt signal for suspending the operation of said background means and for controlling the operating modes of at least ones of said transmitter circuits in such a way as to effect a start-up operation of said transmitter means.

29. The invention of claims 23 or 24 wherein said background means further includes means for monitoring at least a fire signals within said data set indicative of predetermined parameter of said received data signal and, if said parameter is not within predetermined limits, for initiating remedial action to bring said parameter within said limits.

36. The invention of claims 23 or 24 wherein one of said circuits is an equalizer which has as first and second ones of its operating modes the setting of the coefficients of said equalizer to first and second initial sets of values, respectively.

37. The invention of claims 23 or 24 wherein one of said circuits is an equalizer which has as one of its operating modes the updating of its coefficients in response to ideal reference data and as another of its operating modes the updating of said coefficients in response to data decisions made by said receiver means.

38. The invention of claims 23 or 24 wherein one of said circuits is an equalizer which has a normal operating mode, a start-up mode, and a retrain mode.

24. A data set which includes

receiver means operative for recovering far-end data from a data signal representing said far-end data and received from a voiceband telephone channel, said receiver means including a plurality of individual circuits each of which has at least two selectable operating modes,

initialization means operative for placing at least ones of said circuits in respective initial ones of said operating modes,

background means operative subsequent to the operation of said initialization means, said background means including means for monitoring predetermined signals within said data set and operative in response to a determination from the values of ones of the monitored signals that a fault exists in said data set for providing a fault indication,

means for generating an interrupt signal in response to the initial reception of said data signal, and

interrupt service means operative in response to said interrupt signal for suspending the operation of said background means and for controlling the operating modes of at least ones of said receiver circuits in such a way as to effect start-up operation of said receiver means.

31. The invention of claim 24 wherein said interrupt service means is operative for effecting at least one of said start-up operations in at least two alternate ways depending on the current operating mode of at least one of said circuits and wherein said background means further includes means for predetermining for said interrupt service means, as a function of said current operating mode, which of said alternate start-up operations is to be effected.

39. The invention of claim 24 wherein at least one of said transmitter and receiver means operates at least in part in response to a predetermined set of stored program instructions and wherein said initialization means is further operative for providing said program instructions to said one of said transmitter and receiver means.

40. The invention of claim 24 wherein at least one of said transmitter and receiver means is adapted to operate in accordance with a plurality of alternative signal processing formats and wherein said initialization means is further operative for specifying initial ones of said formats.

41. The invention of claim 39 wherein said plurality of signal processing formats includes scrambling formats, differential encoding formats and modulation formats.

42. The invention of claim 39 wherein said plurality of signal processing formats includes descrambling and differential decoding formats.

43. The invention of claim 41 wherein said plurality of signal processing formats further includes scrambling formats, differential encoding formats, and modulation formats.

44. The invention of claims 39, 40 or 41 wherein said interrupt service means is adapted to specify at least one of said signal processing formats to be used during at least one of said start-up operations.

45. The invention of claim 24 wherein at least one of said transmitter and receiver means is adapted to operate with alternative values for each of a plurality of operating parameters and wherein said initialization means is further operative for specifying initial ones of said parameter values.

46. The invention of claim 44 wherein one of said parameter values is a bit rate.

47. The invention of claim 44 wherein one of said parameter values is a baud rate.

48. The invention of claim 44 wherein one of said parameter values is a carrier frequency.

25. A data set which includes

transmitter means operative for generating in response to near-end data a data signal representing said near-end data, said transmitter means including means for applying said data signal to a voiceband telephone channel,

receiver means operative for recovering far-end data from a data signal representing said far-end data received from a voiceband telephone channel, said transmitter means and said receiver means each including a plurality of individual circuits each of which has at least two selectable operating modes,

initialization means operative for placing at least ones of said circuits in respective initial ones of said operating modes,

background means operative subsequent to the operation of said initialization means, said background means including means for monitoring predetermined signals within said data set and operative in response to a determination from the values of ones of the monitored signals that a fault exists in said data set for providing a fault indication,

means for generating a first interrupt signal in response to an indication from a source external to said data set that operation of said transmitter means is desired,

means for generating a second interrupt signal in response to the initial reception of said received data signal, and

interrupt service means operative in response to said first and second interrupt signals for suspending the operation of said background means and for controlling the operating modes of ones of said circuits in such a way as to effect start-up operations of said transmitter means and said receiver means, respectively.

27. The invention of claim 25 wherein at least one of said user-controlled signals is indicative of a test to be performed by said data set.

28. The invention of claim 25 wherein at least one of said user-controlled signals is indicative of a change to be made in the operating mode of at least one of said circuits.

30. The invention of claim 28 wherein said receiver means is adapted to operate utilizing a plurality of alternative signal processing formats and wherein said remedial action includes causing said receiver means to operate with at least one changed operating mode or signal processing format.