| 摘要 |
PURPOSE:To execute hidden-surface processing utilizing Z buffer method within the memory access time of one cycle by including a comparator, a means for inputting a part of word data and a part of input data to the comparator and a means for controlling the writing of input data in a memory cell in the semiconductor storage device. CONSTITUTION:An address 5 inputted from the external is inputted to a row decoder 8 to select respectively corresponding data strings from a picture element memory 13 and a Z memory 14. Then the address 5 is inputted to a picture element column decoder 11 and a Z column decoder 12 to select corresponding picture element value and Z value from the data strings. When the Z value inputted from the external is smaller, the picture element value 6 and the Z value 7 are written in the positions already selected by the address 5 in both the memories 13, 14 and the storage data of the positions in the memories 13, 14 are updated. Thereby, the writing time required for writing picture element data in the picture element memory can be completed by one memory cycle. |
