ADDRESS CONVERTING CIRCUIT AND ORTHOGONAL CONVERTING CIRCUIT EQUIPPED WITH THE SAME

摘要

PURPOSE:To reduce the storage capacity of a 1st semiconductor storage device and reduce the circuit scale by inserting inversion/ noninversion circuits before and behind the 1st semiconductor storage device. CONSTITUTION:The inversion/noninversion circuit 17 consists of an inverting circuit 5 equipped with inverters 51-55 and a selector 6 equipped with changeover switches 61-65. The output terminals of the changeover switches 61-65 are connected to RC1-RC5 of an address conversion ROM 15A. The inversion/ noninversion circuit 18, on the other hand, consists of an inverting circuit 7 equipped with inverters 70-75 and a selector 8 equipped with changeover switches 80-85. The input terminals of the inverters 70-75 are connected to RA0-RA5 of the address conversion ROM 15A. The changeover switches 80-85 are controlled with a zigzag address CO. This constitution can convert a zigzag address C into a raster address A irrelevantly to the value of CO by using the address conversion ROM 15 whose storage capacity is a half as large as before.