Kabushiki Kaisha Toshiba

Moriyasu Banno

Hiroyuki Watanabe

Tatsuo Inoue

Tomotaka Saito

Hiroshi Itaya

Tomoaki Shoda

Masakazu Miyake

A semiconductor device is provided with test-subject circuit, test-irrelevant circuit, first pads used for the test-subject circuit, and second pads used for the test-irrelevant circuit. The first pads include a plurality of divided pad portions while each of the second pads is provided with a single pad portion.

Semiconductor integrated circuit device having pads respectively provided with pad portions

A data processing system incorporates a central processing unit to decode and execute given instructions; a memory to store given data; a bus interface unit, provided between the central processing unit and the memory, to start a read bus cycle to read data from the memory, a write bus cycle to write data to the memory, or a dummy bus cycle different from the read and write bus cycles; and a read-modify-write unit provided between the central processing unit and the bus interface unit. The read-modify-write unit includes a modify-requirements buffer to store modify requirements having modify data output from the central processing unit and an operation control signal; and a modify operation circuit to apply an operation processing to read data output from the bus interface unit with the modify data output from the modify-requirements buffer under the operation control signal to output an operation result to the bus interface unit, as write data.

System having read-modify-write unit

An instruction code conversion unit, an information processing system provided with the instruction code conversion unit and an instruction code generation method for generating instruction codes which are converted by the instruction code conversion unit are described. The efficiency of coding of the program is improved by making use of an existing processor as selected is used without modification. An instruction code conversion unit performs conversion of the address of a native instruction code to the address of the corresponding compressed instruction code in a program memory by shifting the address of the native instruction code as outputted from the processor to the right by one bit.

Instruction code conversion unit and information processing system and instruction code generation method

A control system comprises an interrupt controller, having vector access signal output mechanism for outputting a vector access signal, which is activated when a start address is read out from a vector holder, and a central processing unit (CPU), comprising a present mask holder, which holds a present mask level, and a previous mask holder, which holds a previous mask level, wherein the CPU compares the interrupt level and the present mask level, and, when the interrupt level is higher than the present mask level, copies a value of the present mask level holder into the previous mask level holder, reads out a start address of an interrupt processing program corresponding to an accepted interrupt request from the vector holder, starts executing the interrupt processing program, and copies the interrupt level into a present mask level holder by means of an activated vector access signal.

Method and apparatus for handling interrupts through the use of a vector

A microcomputer has an internal program memory for storing a program and/or data, an external program memory for storing a program and/or data, a CPU for outputting a first address, for fetching an instruction stored at a location indicated by the first address from the internal program memory or the external program memory and executing the fetched instruction, and for, when the instruction instructs to read out a program or data, outputting a second address, and an internal program memory read protection circuit for receiving the first address output from the CPU and checking if the first address is present in the address space of the internal program memory, for receiving, from the CPU, the second address indicating the storage location of a program or data to be read out in accordance with the instruction and checking if the second address is present in the address space of the internal program memory. When the first address is not present in the address space of the internal program memory and the second address is present in the address space of the internal program memory, the internal program memory read protection circuit outputs a read inhibition signal to the internal program memory. The internal program memory does not execute a read access upon reception of the read inhibition signal.

Microcomputer having a read protection circuit to secure the contents of

An operation unit has operation circuits (aL, aH), temporary registers (xL, yL, xH, yH) arranged just before the operation circuits, registers (R1, R2, R3, R4) arranged if required, and data buses (d1L, d2L, d1H, d2H) for transferring data among the operation circuits, temporary registers, and registers. Data to be processed are divided, are transferred to the operation circuits through the data buses, and are simultaneously and independently processed by the operation circuits. When a result of the preceding operation affects the following operation, data except the result of the preceding operation are transferred from the registers to the temporary registers before starting the operations. These techniques shorten a processing time.

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Kanagawa-ken, Japan

Moriyasu Banno