Semiconductor device with non-volatile memory and random access memory
View Patent ↗A semiconductor device including a large capacity non-volatile memory and at least one random access memory, said the access time of said device being matched to the access time of each random access memory. The semiconductor memory device is comprised of: a non-volatile memory FLASH having a first reading time; a random access memory DRAM having a second reading time which is more than 100 times shorter than the first reading time; a circuit that includes a control circuit connected to both the FLASH and the DRAM and enabled to control accesses to those FLASH and DRAM; and a plurality of I/O terminals connected to the circuit. As a result, FLASH data is transferred to the DRAM before the DRAM is accessed, thereby matching the access time between the FLASH and the DRAM. Data is written back from the DRAM to the FLASH as needed, thereby keeping data matched between the FLASH and the DRAM and storing the data.
1. A memory module mounted in a package, comprising:
a non-volatile memory;
a random access memory;
a controller controlling the non-volatile memory and the random access memory;
a controller controlling the non-volatile memory and the random access memory;
a command register written an instruction code;
a plurality of external command signal terminals;
a plurality of external address terminals; and
a plurality of external data terminals, wherein the controller reads out data from the non-volatile memory and writes the data read out from the non-volatile memory to the random access memory when a load instruction code is written into the command register, wherein
when command signals inputted to the plurality of command signal terminals indicate a write operation and address signal inputted to the plurality of external address terminals indicate an access to the command register, the load instruction code is written into the command register via the plurality of external data terminals, and
when command signals inputted the plurality of command signal terminals indicate the write operation and address signal inputted to the plurality of external address terminals indicates an access to the random access memory, data inputted to the plurality of external data terminals is written into the random access memory.
2. A memory module according to claim 1 , wherein
the command register is further written a start address of the non-volatile memory via the plurality of external data terminals, and
in the load operation, the controller starts to read out data from the start address written in the command register to the random access memory.
3. A memory module according to claim 2 , wherein
the command register is further written an end address of the non-volatile memory via the plurality of external data terminals, and
the load operation, the controller reads out data from the start address to the end address and writes the data read out from non-volatile memory.
4. A memory module according to claim 1 , wherein the memory module outputs data stored in the random access memory even if the load operation does not finish when command signals which indicate a read operation are inputted from the plurality of external command terminals and address signals which indicate the access to the random access memory are inputted from the plurality of external address terminals during the load operation.
5. A memory module according to claim 1 , wherein when the command signals indicating a read operation are inputted from the plurality of command terminals during the load operation, the controller stops to perform the load operation and start a read operation from the random access memory.
6. A memory module according to claim 1 , wherein the data read out from non-volatile memory is written into the random access memory via an error collection circuit.
7. A memory module according to claim 1 , wherein the random access memory is a dynamic random access memory, and a capacitance of the dynamic random access memory is larger than a capacitance of the non-volatile memory.
8. A memory module according to claim 1 , wherein the memory module uses a SRAM interface.
9. A memory module according to claim 1 , wherein
the controller reads out data from the random access memory and writes the data read out from the random access memory to the non-volatile memory in a store operation when a store instruction code is written into the command register, and
when command signals inputted to the plurality of command signal terminals indicate the write operation and address signal inputted to the plurality of external address terminals indicate the access to the command register, the store instruction code is written into the command register via the plurality of external data terminals.
10. A memory module according to claim 9 , wherein to write data from the outside of the memory module, the data from the outside of the memory module is written into the random access memory and then the data written into the random access memory is transfer to the non-volatile memory by performing the store operation.
11. A memory module, comprising:
a non-volatile memory;
a random access memory;
a command register;
a plurality of external command terminals;
a plurality of external address terminals; and
a plurality of external data terminals, wherein
the memory module transfers data from the non-volatile memory to the random access memory in a load operation,
the load operation starts by writing a load instruction code to the command register,
the load instruction code is written into the command register via the plurality of external data terminals when command signals which indicate a write operation are inputted from the plurality of external command terminals and address signals which indicate an access to the command register is inputted from the plurality of external address terminals, and
the memory module writes data inputted to the plurality of external data terminals to the random access memory when command signals which indicate the write operation are inputted from the plurality of external command terminals and address signals which indicate an access to the random access memory are inputted from the plurality of external address terminals.
12. A memory module according to claim 11 , wherein
a start address is written into the command register via the plurality of external data terminals, and
the memory module starts to read data from the start address of the non-volatile memory.
13. memory module according to claim 12 , wherein an end address is written into the command register via the plurality of external data terminals, and the memory module transfers data from the start address to the end address.
14. A memory module according to claim 11 , wherein the memory module outputs data stored in the random access memory even if the load operation doesn't finish when command signals which indicate a read operation are inputted from the plurality of external command terminals and address signals which indicate the access to the random access memory are inputted from the plurality of external address terminals during the load operation.
15. A memory module according to claim 11 , wherein the memory module stops the load operation and performs the read operation when command signals which indicate the read operation are inputted from the plurality of external command terminals and address signals which indicate an access to the random access memory are inputted from the plurality of external address terminals during the load operation.
16. A memory module according to claim 11 , further comprising:
an error collection circuit, wherein the data stored in the non-volatile memory is transferred to the random access memory via the error collection circuit.
17. A memory module according to claim 11 , wherein
the random access memory is a dynamic random access memory, and
a capacitance of the dynamic random access memory is larger than a capacitance of the non-volatile memory.
18. A memory module according to claim 11 , wherein the memory module uses a SRAM interface.
19. A memory module according to claim 11 , wherein
the memory module transfers data from the random access memory to the non-volatile memory in a store operation, and
the store operation starts by writing a store instruction code to the command register, and wherein the store instruction code is written to the command register via the plurality of external data terminals when command signals which indicate the write operation are inputted from the plurality of external command terminals and address signals which indicate the access to the command register is inputted from the plurality of external address terminals.
20. A memory module according to claim 19 , wherein to write data from the outside of the memory module, the data from the outside of the memory module is written into the random access memory and then the data written into the random access memory is transfer to the non-volatile memory by performing the store operation.