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US4658294A Expired / Lapsed US ⏱️ 0.0 years remaining

Direct memory access control device for use in teletext signal receiving apparatus

Assignee: LG Electronics Inc
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Filing: 1985-12-27
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Granted: 1987-04-14
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Expires: 2005-12-27
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Abstract

Abstract A direct memory access control device as a part of a teletext adaptor is equipped with a data separating element, a data receiving element including an improved direct memory access control device as a part, and a data processing element. The direct memory access control device comprises a serial/parallel convertor, a D-flip flop, an OR gate, a byte synchronization detector, a multivibrator, a 4 division counter, a 8 division counter, a 64 division counter, a RAM, a multiplexer and so forth. The teletext data can be stored in RAM. During an interval between the remaining video signal periods, the microprocessor can process signals so that all the elements may be simplified and the cost entailed therefore may be lowered accordingly.

Inventors

  • 👤 Chong S. Park

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 21:01
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/08; H04N7/087; H04N7/088; H04N7/0882

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 186 words
In a teletext adaptor comprising a data separating element, a data receiving element including an improved direct memory access control device as a part and a data processing element, the improved direct memory access control device comprising; a serial/parallel converter having an output connected to an input of a byte synchronization detector and a D-input of a flip flop; a first OR gate having an input connected to an output of the byte synchronization detector, another input connected to an output of a multivibrator which is supplied with the output of the byte synchronization detector, and an output connected to a clock input of a 4 division counter, an input of a 64 division counter and a terminal of an 8 division counter; a RAM having an input connected to an output of the flip flop and to a data bus; and a second OR gate having an input connected to an output of a NAND gate, another input connected to receive a vertical blanking internal signal, and and output connected to a terminal of the RAM which also receives an address input from a multiplexer.
Claim 2
Dependent Claim 186 words
In a teletext adaptor comprising a data separating element, a data receiving element including an improved direct memory access control device as a part and a data processing element, the improved direct memory access control device comprising; a serial/parallel converter having an output connected to an input of a byte synchronization detector and a D-input of a flip flop; a first OR gate having an input connected to an output of the byte synchronization detector, another input connected to an output of a multivibrator which is supplied with the output of the byte synchronization detector, and an output connected to a clock input of a 4 division counter, an input of a 64 division counter and a terminal of an 8 division counter; a RAM having an input connected to an output of the flip flop and to a data bus; and a second OR gate having an input connected to an output of a NAND gate, another input connected to receive a vertical blanking internal signal, and and output connected to a terminal of the RAM which also receives an address input from a multiplexer.

References Cited (Backward Citations)

US4577227A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-13 1990-10-13 1991-04-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-13 1994-10-13 1995-04-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-13 1998-10-13 1999-04-14 $7700.00 Window Closed / Lapsed

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