(19)
(11) EP 0 529 934 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
22.12.1993 Bulletin 1993/51

(43) Date of publication A2:
03.03.1993 Bulletin 1993/09

(21) Application number: 92307590.7

(22) Date of filing: 19.08.1992
(51) International Patent Classification (IPC)5: G09G 3/36
(84) Designated Contracting States:
DE FR GB

(30) Priority: 23.08.1991 US 749071

(71) Applicant: MOTOROLA, INC.
Schaumburg, IL 60196 (US)

(72) Inventors:
  • Wong, Harvey
    Wong, Tai Sin, Kowloon (HK)
  • Tsang, Hoi-cheun
    Block 7, 16/FL Kowloon (HK)

(74) Representative: Hudson, Peter David et al
Motorola European Intellectual Property Midpoint Alencon Link
Basingstoke, Hampshire RG21 7PL
Basingstoke, Hampshire RG21 7PL (GB)


(56) References cited: : 
   
       


    (54) LCD driver and control unit


    (57) A LCD controller/driver utilizes a bi-directional data ring to enable quick and easy data alteration and shifting. The controller/driver couples cascaded segment drivers (32, 34) to a row data serial interface (24) which links the drivers with a micro-processor unit (MPU) (18). The cascaded segment drivers coupled to the row data serial interface define the bi-directional data ring. Display data input into the segment drivers may be altered by shifting the data into the data ring and transmitting such data to, or through, other segment drivers and to the row data serial interface, where the data is altered by inputs from the MPU. Two data rings are established by coupling the respective segment drivers in series with the row data serial interface. The two data rings generally operate independently. However, when data is to be transferred from one screen to another, such as during a vertical scroll, the two data rings are coupled together and the data is transferred serially. The data rings allow for easy alterations and smooth scrolling in both the horizontal and vertical directions.






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