Memory tuning system with different speeds in program and operate modes
AssigneeZenith Radio Corporation
InventorAkio Tanaka
Life of this patent
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Abstract
An all-channel two mode television tuning system includes a two speed counter for generating channel numbers to adjust tuning. An 82 .times. 1 bit read/write memory is addressed in a program mode by the generated channel numbers to provide locations for storage of signals for tuning to preselected channels. In the operate mode channel numbers are again generated and logic circuitry accesses the memory locations to determine if generated channel numbers correspond to preselected channel numbers. Mode selection means control the two speed counter to provide a faster speed in the operate mode than in the program mode. Channel number generation is automatically stopped in the operate mode when correspondence with a preselected channel number is determined.
Claims10
A television tuning system having counting means, generating sequential channel number information for tuning all channels, coupled to read/write memory means accessed by said channel number information and having a plurality of addressable locations for storage and recall of signals related to selected channel number information, said tuning system having a program mode for storage of said signals and an operate mode for recall from said memory means of said signals to cause tuning to channels corresponding to the addresses of individual locations of said memory means, including:
- mode selection means for establishing either of said two modes;
- and
- sequence control means, coupled to said counting means and responsive to said mode selection means, for changing the counting speed of said counting means to produce different access speeds for said memory locations in said two modes.
A television tuning system comprising:
- two speed counting means generating sequential channel numbers for tuning all channels;
- memory means coupled to said counting means, accessed by said channel numbers, and having a separate addressable location for storage and recall of signals related to each selected channel number;
- said tuning system having a program mode for storage of said signals in said memory means and an operate mode for recall of said signals from said memory means to cause tuning to channels corresponding to said addressable locations of said memory means;
- clock means generating timing pulses at regular intervals;
- means coupled to said clock means and said two speed counting means for deriving counting pulses at two different rates;
- mode selection means for establishing either of said two modes;
- logic means controlling said means deriving counting pulses responsive to said mode selection means for supplying said counting means with counting pulses at a lower rate in said program mode than in said operate mode;
- means coupled to said two speed counting means communicating to the viewer the channel number generated;
- and
- means operable in said program mode and coupled to said memory means to generate and store signals related to selected channel numbers.
Dependencies are inferred from the claim text.