Sharp Kabushiki Kaisha Corporation

Other

Nippon Telegraph and Telephone Corporation

Ryuichi Ogawa

Tadao Takeda

Kazuhiro Yaegawa

Masaki Wakabayashi

Hiroki Suto

Masahiro Yoshizawa

Masaaki Tanno

Susumu Kurioka

Kenji Ohno

Hiroki Sutou

An IC card according to the present invention comprises, a built-in coprocessor for an auxiliary arithmetic in addition to a main arithmetic processing unit, an interval timer for outputting an interrupt request signal upon lapse of a set time shorter than the frame waiting time, and coprocessor control means for controlling the coprocessor operation by suspending supply of an operation clock to the coprocessor in accordance with the output of the interrupt request signal and resuming supply of the operation clock to the coprocessor in accordance with a predetermined response input from an external device. Upon receipt of a command from the external device, the contents of the command are determined, and the time shorter than the frame waiting time is set in the interval timer thereby to start the interval timer.

IC card with built-in coprocessor for auxiliary arithmetic, and control method thereof

A 1-chip microcomputer of the present invention has (a) a monitor flag for setting a flag indicating that a specified address space is accessed, (b) an access permission address range setting register, for setting an address range in which an access is permitted while the flag is set, (c) an access permission area detection circuit for judging whether the access is made within the address range thus set, (d) an access permission setting register, for setting whether or not an access with respect to an address other than the address range should be permitted, and (e) memory read-out control circuit and memory writing control circuit for controlling an access with respect to a nonvolatile memory based on a result thus judged and content set by the access permission setting register. With the arrangement, it is possible to provide a 1-chip microcomputer that maintains the security among application programs.

1-chip microcomputer having controlled access to a memory and IC card using the 1-chip microcomputer

A 1-chip microcomputer having a built-in nonvolatile memory includes at least one erasable flash memory provided in a memory space of the microcomputer, a boot ROM for storing an initial program to start up the 1-chip microcomputer and a transfer program to transfer the initial program to the flash memory, and control means for, when the flash memory stores no program, transferring the initial program to the flash memory in accordance with the transfer program and subsequently removing the boot ROM from the memory space. Consequently, even if a new program is additionally stored to the nonvolatile memory in the 1-chip microcomputer, the additional program can be carried out.

Microcomputer having built-in nonvolatile memory for simultaneous use as a program area and a data area

A microcomputer with a sound effect output function, comprising a register 24 for temporarily storing a parameter specifying a sound effect to be output, a sound effect generating block 26 for outputting a signal representing a sound effect according a parameter supplied from the register 24, an output pattern setting register 25 for temporarily storing a repetition pattern of a sound effect signal supplied by the sound effect generating block 26, and an output control block 28 for outputting the sound effect signal, supplied from the sound effect generating block 26, according to the repetition pattern supplied from the output pattern setting register 25.

Microcomputer with function to output sound effects

Growing community of inventors

Ichihara, Japan

Ryuichi Ogawa