US 8,429,634 B2Granted

Semiconductor device, memory circuit, and machine language program generation device, and method for operating semiconductor device and memory circuit

AssigneeSemiconductor Energy Laboratory Co., Ltd.

InventorsHiroki Dembo, Yoshiyuki Kurokawa, Masami Endo

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Abstract

A semiconductor device has an arithmetic processing circuit provided with an arithmetic circuit and a control circuit and a memory circuit provided with a ROM and a RAM, where the arithmetic processing circuit and the memory circuit are connected to each other through an address bus and a data bus, a machine language program executed using the arithmetic processing circuit is stored in the ROM, the RAM has a plurality of banks, processing data obtained by executing the machine language program is divided into a plurality of stacks to be written to the plurality of banks, and the arithmetic processing circuit is operated in accordance with the machine language program so that, in the plurality of stacks stored in the plurality of banks, a stack of which data is not used until the machine language program is terminated is omitted and contiguous stacks are written to the same bank.

Claims10

Dependent claims

A semiconductor device comprising:

an arithmetic processing circuit;
a ROM;
a RAM;
and
a memory control circuit,
wherein the arithmetic processing circuit is configured to execute a program to generate processing data and then terminate the program,
wherein the ROM is configured to store the program, the program having stack analysis means and optimization means,
wherein the RAM comprises a plurality of memory blocks, a border being defined between adjacent ones of the memory blocks
wherein the processing data is divided into a plurality of stacks to be stored in the RAM,
wherein the stack analysis means analyzes the stacks to obtain an analysis result that identifies a status of use of the stacks, including operations writing to the stacks, operations reading from the stacks, identification of contiguous writing stacks that do not cross the border between adjacent memory blocks, and identification of contiguous writing stacks that do cross the border between adjacent memory blocks, and provides a stack pointer,
wherein the optimization means reads the analysis result and performs optimization of the processing data by
identifying stacks that are written to but are not read until after the program terminates,
reusing the identified stacks for rewriting of additional processing data to reduce the number of stacks used for performing writing of the data, and
rearranging contiguous stacks that cross the border between adjacent memory blocks so that writing of such contiguous stacks occurs between borders of the memory blocks so that power consumption of the RAM can be reduced, and
wherein the memory control circuit stores the optimized stacks in the memory blocks.

12 more elements

A semiconductor device comprising:

an arithmetic processing circuit;
a ROM;
a RAM;
and
a memory control circuit,
wherein the arithmetic processing circuit is configured to execute a program to generate processing data and then terminate the program,
wherein the ROM is configured to store the program, the program having stack analysis means and optimization means,
wherein the RAM comprises a plurality of memory blocks, a border being defined between adjacent ones of the memory blocks
wherein the processing data is divided into a plurality of stacks to be stored in the RAM,
wherein the stack analysis means analyzes the stacks to obtain an analysis result that identifies a status of use of the stacks, including operations writing to the stacks, operations reading from the stacks, identification of contiguous writing stacks that do not cross the border between adjacent memory blocks, and identification of contiguous writing stacks that do cross the border between adjacent memory blocks, and provides a stack pointer,
wherein the optimization means reads the analysis result and performs optimization of the processing data by
identifying stacks that are written to but are not read until after the program terminates,
reusing the identified stacks for rewriting of additional processing data to reduce the number of stacks used for performing writing of the data, and
rearranging contiguous stacks that cross the border between adjacent memory blocks so that writing of such contiguous stacks occurs between borders of the memory blocks so that power consumption of the RAM can be reduced,
wherein the memory control circuit stores the optimized stacks in the memory blocks, and
wherein the program is optimized using RAM design information comprising the number of memory blocks included in the RAM and a capacity of each of the memory blocks included in the RAM.

13 more elements

Dependencies are inferred from the claim text.