Abstract: An image processor which is connected to a system bus that connects a processor for forming graphic command related to image processing to a main memory that holds command and original image data, and draws image on the frame buffer based upon said graphic command from said processor, wherein said graphic processor has a data bus change-over unit which connects said system bus to a first data bus that is connected to a graphic data memory holding said graphic command and said original image data, or connects said first data bus to a frame buffer which holds the data to be displayed. The image processor realizes a high-speed processing at a reduced cost by using a graphic memory bus coupled to a graphic processor.

Abstract: A data processor comprising: a bus control circuit adapted to be interfaced with a synchronous DRAM which can be accessed in synchronism with a clock signal; a plurality of data processing modules coupled to said bus control circuit for producing data and addresses for accessing a memory; and a clock driver for feeding intrinsic operation clocks to said data processing modules and for feeding the clock signal for accessing said memory in synchronism with the operations of said data processing modules to be operated by the operation clock signals, to the outside.

Abstract: A data processor comprising: a bus control circuit adapted to be interfaced with a synchronous DRAM which can be accessed in synchronism with a clock signal; a plurality of data processing modules coupled to said bus control circuit for producing data and addresses for accessing a memory; and a clock driver for feeding intrinsic operation clocks to said data processing modules and for feeding the clock signal for accessing said memory in synchronism with the operations of said data processing modules to be operated by the operation clock signals, to the outside.

Abstract: A mesomorphic compound represented by the formula: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms; R.sub.2 denotes an alkyl group having 2-10 carbon atoms; X denotes a single bond or --O--; Y denotes --OCH.sub.2 --, ##STR2## Z denotes a single bond, ##STR3## respectively and independently denote ##STR4## k, l and n are respectively 0, 1 or 2 satisfying the relation of k+l+n=2 or 3; C* denotes an asymmetric carbon atom. The mesomorphic compound, when added as a component, provides a liquid crystal composition showing an improved field respective characteristic or is effective in preventing occurrence of a reverse domain.