Abstract: The data quantizing device quantizes coefficients subjected to orthogonal transform using a quantizing table. The device includes a comparing unit for deciding whether or not quantized data will be ‘0’ by comparing the orthogonal transformed coefficients with corresponding coefficients in the quantizing table, and a control unit for controlling the quantization so that only the orthogonal transformed coefficients with the quantized coefficients of not ‘0’ are quantized. The image data compressing device employs this data quantizing device, and this results in not only curtailing power consumption but also increasing the processing speed.

Abstract: A data transfer device is provided which can perform time management of data transfer in real time for effective use of communication channels. The data transfer device according to the present invention includes a memory for storing firmware for controlling data transfer and a communication circuit for transferring data under control of the firmware. The communication circuit has a timer for measuring a time. In accordance with the measured value of the timer, a communicating party is controlled by the communication circuit independently from the control by the firmware. Here, controlling the communicating party includes to perform polling on the communicating party and to disconnect the link with the communicating party when the polled communicating party does not respond.

Abstract: To order to provide an encoding/decoding device capable of reducing the memory area required and speeding up encoding processing, an encoding/decoding device according to the invention includes a data encoder for reading a size representing a code length of each code word stored in memory, and an offset representing the numerical difference between a base, representing a minimum or maximum value in code words having the code length represented by this size, and the code word, using an address designated by a run length and a group number, outputting a minimum or maximum value in a code word having a code length designated by the size with a multiplexer, adding the base and the offset, and outputting a code of a code word corresponding to the run length and group number.