Abstract: Original data consisting of three-dimensional coordinate data, color, &agr;-value and the like of a polygon, which is obtained through a geometrical operation by a geometrical operation processing unit (2) on the basis of polygon definition data (1) is stored into a memory (4A or 4B) in advance as geometrical-operation processed three-dimensional data (D1). That allows generation of three-dimensional graphics drawing data only by a drawing operation processing unit (3) on the basis of the geometrical-operation processed three-dimensional data (D1) stored in the memory (4B). With this constitution, a three-dimensional graphics system which ensures reduction in cost and power consumption can be obtained.

Abstract: A three-dimensional graphics drawing apparatus includes a geometrical operation unit generating vertex data of a polygon, an offset register storing an offset value for the vertex data of the polygon generated by the geometrical operation unit, an offset operating circuit adding the offset value stored in the offset register to the vertex data of the polygon output from the geometrical operation unit, and a drawing unit drawing the polygon based on the vertex data after the addition by the offset operating circuit. Therefore, even with a geometrical operation unit having relatively low process performance, it becomes possible to draw a primitive which changes with motion, for example, at high speed.

Abstract: In the three-dimensional graphics drawing apparatus, a color register has an &agr; register in which a Z-coordinate value of an object is set as its &agr; value. A drawing unit draws the object based on coordinate data stored in a coordinate register and color data stored in the color register. Accordingly, the degree of transparency of a drawing object that is closer to the front increases, and a portion that is hidden behind the drawing object becomes apparent. Visibility is thus increased.

Abstract: A signal is transmitted to/from an analog circuit portion and a digital circuit portion through an interface circuit portion. Analog circuit portion, digital circuit portion and interface circuit portion are externally supplied with power from different power supplies and provided in different well regions.

Abstract: A data table includes a source pointer indicating a starting address of drawing data, a destination pointer indicating a destination of drawing data to be transferred, and a data length indicating a data length of drawing data to be transferred. Data table may indicate drawing data to be drawn. Thus frames may share drawing data. As such the amount of drawing data can be reduced.

Abstract: A three-dimensional graphics drawing apparatus includes a geometrical operation unit generating vertex data of a polygon, an offset register storing an offset value for the vertex data of the polygon generated by the geometrical operation unit, an offset operating circuit adding the offset value stored in the offset register to the vertex data of the polygon output from the geometrical operation unit, and a drawing unit drawing the polygon based on the vertex data after the addition by the offset operating circuit. Therefore, even with a geometrical operation unit having relatively low process performance, it becomes possible to draw a primitive which changes with motion, for example, at high speed.

Abstract: A three-dimensional graphic processing device includes an identifying portion for identifying whether the vertex data of a polygon to be drawn is an absolute value or a relative value, an operation unit for operating to obtain the absolute value of vertex data identified as a relative value by the identifying portion and a set up circuit for generating data necessary for drawing based on the absolute value of the vertex data obtained by the operation unit. The operation unit operates to obtain the absolute value of vertex data identified as a relative value by the identifying portion, and therefore the vertex data of a polygon can be expressed by a relative value. As a result, the data amount of polygon data can be reduced, which permits the drawing throughput to be improved.

Abstract: In a rendering processing system having a rendering memory for storing rendering pixel data generated by a rendering operation circuit and a display memory for storing the image data of a current frame read out from the rendering memory, the display memory stores only the pixel data read out from the rendering memory with prescribed information excluded therefrom. Thus, it is possible to decrease the storage capacity of the display memory and also reduce the time required for writing data into the display memory.

Abstract: To facilitate the expansion and addition of instruction functions and to reduce development costs and time for products comprising new functions, the microaddress and mask address of a microinstruction are compared by a microaddress comparing circuit. When they correspond, an extended micropointer for generating an extended microaddress is selected by a pointer selecting circuit so as to access extended microinstruction memory in place of the micropointer and to exchange the function of a microinstruction specified by a microaddress with the function of an extended microinstruction.

Abstract: In order to make possible expansion or change of the function by microinstruction without revising an instruction decoder in a microprogram control circuit, each time microinstruction memory means is accessed by micro address of the microinstruction selected by the instruction decoder, a microinstruction control circuit activates expansion microinstruction memory means in accordance with an information which is set in an information bit at each microinstruction, and the microinstruction is changed to an expansion microinstruction.