Binary to unary decoder for a video digital to analog converter
AssigneeCommodore Electronics Limited
InventorRobert J. Rabile
Life of this patent
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Abstract
A binary to unary decoder for a video digital to analog converter is cascadeable in both a horizontal and a vertical direction. Video data is transmitted from a video data source and received by a plurality of unary decoders which convert the video data to a corresponding number of unary digits having comparable value. The unary decoders are arranged in a number of cascaded levels. A plurality of cascaded unary block drivers receive the unary digits and transit unary output digits to a video data bus. The plurality of unary block drivers are arranged in a number of tiers having a predetermined number of individual unary block drivers. The predetermined number of cascaded unary block drivers are enabled based upon the numerical value of the video data.
Claims8
A binary to unary decoder for a video digital to analog converter which is cascadeable in both a horizontal and a vertical direction, the decoder comprising:
- video data means for transmitting video data from a video data source, said video data comprising a predetermined number of binary input bits;
- a plurality of unary decoders for receiving said video data and converting said video data to a corresponding number of unary digits having comparable value, said unary decoders being arranged in a number of cascaded levels, the number of levels of cascaded unary decoders being related to the number of binary input bits received in the following relationship:
- N=[x/D]
- wherein N=the number of levels of unary decoders
- x=the total number of binary input bits;
- D=number of binary input bits contained within a single unary decoder;
- [ ]=greatest integer number;
- a plurality of cascaded unary block drivers for receiving the unary digits and transmitting unary output digits to a video data bus, the plurality of unary block drivers being arranged in a number of tiers having a predetermined number of individual unary block drivers, the number of unary block drivers in each tier being determined by the following relationship:
- U.sub.t =2.sup.dt for t=1 to (N-1)
- wherein U.sub.t =the number of individual unary block drivers in a given tier;
- .sup. d =the number of unary digits in an individual unary block driver which is less than or equal to 2.sup.D ;
- t=particular tier;
- and
- activating means for activating a predetermined number of cascaded unary block drivers corresponding to the numerical value of the video data.
A binary to unary decoder which is cascadeable in both a horizontal and a vertical direction comprises:
- data means for transmitting data from a data source, said data means comprising a predetermined number of binary input bits;
- a plurality of unary decoders for receiving said data and converting said data to a corresponding number of unary digits having comparable value, said unary decoders being arranged in a number of cascaded levels, the number of levels of cascaded unary decoders being related to the number of binary bits receives in the following relationship:
- N=[X/D]
- wherein N=the number of levels of unary decoders
- x=the total number of binary bits;
- D=number of binary bits contained within a single unary decoder;
- [ ]=greatest integer number;
- a plurality of cascaded unary block drivers for receiving the unary digits and transmitting the unary output digits to a data bus, the plurality of unary block drivers being arranged in a number of tiers having a predetermined number of individual unary block drivers, the number of unary block drivers in each tier being determined by the following relationship:
- U.sub.t =2.sup.dt for t=1 to (N-1)
- wherein U.sub.t =the number of individual unary block drivers in a given tier;
- 2.sup.d =the number of unary digits in an individual unary block driver which is less than or equal to 2.sup.D ;
- and
- t 32 particular tier;
- enabling means for enabling the unary digits to be transmitted through the unary block driver unmodified to the databus;
- and
- forcing means for forcing all of the unary output digits of an individual unary block driver to a high state.
Dependencies are inferred from the claim text.