Abstract: A cathode ray tube controller holds a write-in address and displaying image data or a read-out address from a central processing unit. The cathode ray tube controller makes access to a memory by a write-in or read-out address from the central processing unit during a period in which the displaying image data in a horizontal scanning period are not read out from the memory, so that the read or write operation with respect to the memory can be carried out during the horizontal scanning period.

Abstract: An analog-to-digital converter comprising one or more charging and discharging circuits (C.sub.A and/or C.sub.B), a control circuit (6' and/or 6"), and a timer-counter (7). The control circuit performs the discharging operation alternately and continuously on the charging and discharging circuits. The timer-counter counts a predetermined number of times the discharging operation is performed so as to create a digital value (T).

Abstract: A one-chip microcomputer including a central processing unit, a direct memory access controller and a random-access memory. In a DMA operation mode, data stored in the random-access memory is transmitted through common terminals to the exterior by means of a time-division control circuit or registers for parallel-serial conversion. The common terminals are also used for a CPU operation mode.

Abstract: A semiconductor read only memory device comprises bit lines, word lines, a load transistor, a multiplexer including a plurality of transistors, and a memory cell array in which each memory cell has one transistor having a gate connected to one of the word lines and corresponding to one of the bit lines connected to the transistors of the multiplexer. A gate transistor is inserted between the load transistor and the multiplexer, and a gate voltage control circuit, for selectively providing a higher level signal and a lower level signal, is connected to the gate transistor.