Fujitsu Corporation

Fujitsu Microelectronics Limited

Fujitsu Vlsi Limited

Takashi Sugimoto

Atsushi Fujita

Shigeo Koide

Masaaki Tani

Osamu Tago

Takeshi Fuse

Toshiyuki Igarashi

A data processor capable of preventing the occurrence of overrun, while efficiently performing DMA transfer. An SIO of a data processor starts the transmission of transmission data only when transmission data is stored in a transmission buffer and a reception buffer has no space available for data storage.

Data processor and data communication method

A clock signal generator circuit has a clock generator for generating clock signals to be supplied to a central processing unit and to functional blocks, and clock selectors. The clock generator divides the frequency of a source clock signal, to form a clock signal having an optional period. Namely, the clock generator suppresses at least one active or inactive state of the source clock signal, to generate a clock signal whose period is an integer multiple of that of the source clock signal. The clock selectors receive the clock signals generated by the clock generator and selectively supply them to the CPU and functional blocks. The clock signal generator circuit is capable of operating a microcontroller system at a required minimum speed, to optimize the power consumption of the system.

Clock signal generator circuit using a logical result of an output of a

A data processor including a data control unit having a computing portion, including a first storage unit for writing and reading a first set of data for supporting the computing portion, a second storage unit for writing and reading a second set of data for supporting the computing portion, and an arithmetic unit for calculating the first set of data read out of the first storage unit and the second set of data read out of the second storage unit and outputting result data. The data processor may instead include a data control unit having a computing portion, two or more support units for supporting the computing portion, each including a first storage unit for writing and reading a first set of data for supporting the computing portion, a second storage unit for writing and reading a second set of data for supporting the computing portion, and an arithmetic unit for calculating the first set of data read out of the first storage unit and the second set of data read out of the second storage unit and outputting result data, and a data change-over unit for transferring the resulting data outputted from the support unit to one of another one of the support units and the data control unit.

Data processor having a computing element mounted on a microcontroller

Growing community of inventors

Kasugai, Japan

Takashi Sugimoto