CPU-containing LSI, and optical disk device and LSI device with the same
View Patent ↗The present invention provides a central processing unit-containing large-scale integration (hereinafter, referred to as a “CPU-containing LSI”) in which software stored in an external memory is incorporated partially into a random access memory (hereinafter, referred to as “RAM”) and thereby the capacity of the RAM to be used can be held down, and an optical disk device including the same. In the CPU-containing LSI, the RAM includes a software storage region where software read in from the external memory on a module-by-module basis is stored, and an entry table in which entries are stored, with the entries each containing at least information as to a location and a size of a module stored in the software storage region. The CPU refers to the entry table to decide the location where a module to be read in from the external memory to the software storage region is to be stored, according to an incorporation-location search program.
1. A CPU-containing LSI, comprising:
a CPU;
a RAM; and
a read-in control unit for controlling read-in of software from an external memory to the RAM on a module-by-module basis,
wherein the RAM comprises:
a software storage region where the software read in from the external memory on the module-by-module basis is stored; and
an entry storage region where an entry is stored, the entry including at least information as to a location and a size of a module stored in the software storage region, and
the read-in control unit refers to the entry stored in the entry storage region of the RAM to decide a location where a module to be read in from the external memory to the software storage region of the RAM is to be stored.
2. The CPU-containing LSI according to claim 1 , wherein the read-in control unit erases, from the entry-storage region of the RAM, an entry corresponding to an unnecessary module stored in the software storage region of the RAM.
3. The CPU-containing LSI according to claim 1 , further comprising a ROM that stores at least a read-in control program for controlling read-in of software from the external memory to the RAM,
wherein the read-in control unit is implemented through execution of the read-in control program carried out by the CPU.
4. The CPU-containing LSI according to claim 1 , wherein the CPU and the RAM are contained in one LSI, and the read-in control unit is implemented with a second LSI, the second LSI being located outside the LSI containing the CPU and RAM and being connected thereto.
5. A CPU-containing LSI, comprising:
a CPU;
a RAM;
a read-in control unit for controlling read-in of software from an external memory to the RAM; and
a compression/expansion control unit for controlling compression and expansion of the software,
wherein the RAM comprises:
an execution-program storage region where the software is stored in a form that permits the CPU to refer thereto; and
a compressed-program storage region where at least part of the software is stored in a compressed form,
when the read-in control unit reads in at least part of the software from the external memory to the RAM, the compression/expansion control unit compresses at least part of the software that has been read in to the execution-program storage region and then stores it in the compressed-program storage region, and
when the software stored in the compressed-program storage region is required to be executed, the compression/expansion control unit expands the software and then stores it in the execution-program storage region.
6. The CPU-containing LSI according to claim 5 , further comprising a ROM that stores at least a read-in control program for controlling read-in of software from the external memory to the RAM,
wherein the read-in control unit is implemented through execution of the read-in control program carried out by the CPU.
7. The CPU-containing LSI according to claim 5 , wherein the CPU and the RAM are contained in one LSI, and the read-in control unit is implemented with a second LSI, the second LSI being located outside the LSI containing the CPU and the RAM and being connected thereto.
8. An LSI device, comprising:
a CPU-containing LSI including a CPU and a RAM; and
a read-in control LSI that serves as a read-in control unit for controlling read-in of software from an external memory to the RAM on a module-by-module basis, the external memory being located outside the CPU-containing LSI,
wherein the RAM comprises:
a software storage region where the software read in from the external memory on the module-by-module basis is stored; and
an entry storage region where an entry is stored, the entry including at least information as to a location and a size of a module stored in the software storage region, and
the read-in control unit refers to the entry stored in the entry storage region of the RAM to decide a location where a module to be read in from the external memory to the software storage region of the RAM is to be stored.
9. An LSI device, comprising:
a CPU-containing LSI including a CPU and a RAM; and
a control LSI that serves as a read-in control unit for controlling read-in of software to the RAM from an external memory located outside the CPU-containing LSI and a compression/expansion control unit for controlling compression and expansion of the software,
wherein the RAM comprises:
an execution-program storage region where the software is stored in a form that permits the CPU to refer thereto; and
a compressed-program storage region where at least part of the software is stored in a compressed form,
when the read-in control unit reads in at least part of the software from the external memory to the RAM, the compression/expansion control unit compresses the at least part of the software that has been read in to the execution-program storage region, and then stores it in the compressed program storage region, and
when the software stored in the compressed-program storage region is required to be executed, the compression/expansion control unit expands the software and then stores it in the execution-program storage region.