Controlling write pulse width to non-volatile memory based on free space of a storage
A memory system has a non-volatile memory, a storage accessible at higher speed than the non-volatile memory, to store access information to the non-volatile memory before accessing the non-volatile memory, and a memory controller to control a write pulse width to the non-volatile memory based on a free space of the storage or based on the access information stored in the storage.
1. A memory system comprising:
a non-volatile memory;
a storage accessible at higher speed than the non-volatile memory, to store access information that includes information of whether or not to perform writing or reading to the non-volatile memory, the information including at least one of a write command and a read command; and
a memory controller to select either one of a first mode and a second mode based on a free space of the storage or based on the write and read commands stored in the storage, the first mode being a mode to write data in the non-volatile memory with a first write pulse width, and then perform a verification process to read and inspect the written data, and the second mode being a mode to write data, without the verification process, with a second write pulse width longer than the first write pulse width in the first mode.
2. The memory system of claim 1 , wherein the access information stored in the storage comprises a command that is issued by a processor and is used to access the non-volatile memory, an address to be accessed, and data.
3. The memory system of claim 1 , wherein the memory controller selects the second mode when the storage has no free space or there is no read command to be executed after a write command stored in the storage.
4. The memory system of claim 1 , wherein the non-volatile memory comprises a plurality of memory areas,
wherein the storage stores the access information in association with a memory area to be accessed among the plurality of memory areas.
5. The memory system of claim 4 , wherein the memory controller processes access information to one memory area stored in the storage and then processes in order access information stored in the storage to other memory areas.
6. The memory system of claim 4 , wherein the memory controller selects the first or the second mode for a memory area to be accessed.
7. The memory system of claim 6 , wherein, when selecting the first mode, the memory controller writes data sequentially in one memory area to be written and, after completion of access to the one memory area and before starting access to another memory area, the memory controller performs a verification process to the data written in the one memory area.
8. The memory system of claim 6 , wherein, when read and write commands are included in access information to one memory area, the access information being stored in the storage, the memory controller performs a write process and a read process to the one memory area in order of the read and write commands stored in the storage.
9. The memory system of claim 1 , wherein the storage comprises a volatile memory.
10. The memory system of claim 1 , wherein the non-volatile memory comprises an MRAM (Magnetoresistive Random Access Memory).
11. A processor system comprising:
a processor;
a non-volatile memory accessed by the processor;
a storage accessible at higher speed than the non-volatile memory, to store access information that includes information of whether or not to perform writing or reading to the non-volatile memory, the information including at least one of a write command and a read command; and
a memory controller to select either one of a first mode and a second mode based on a free space of the storage or based on the write and read commands stored in the storage, the first mode being a mode to write data in the non-volatile memory with a first write pulse width, and then perform a verification process to read and inspect the written data, and the second mode being a mode to write data, without the verification process, with a second write pulse width longer than the first write pulse width in the first mode.
12. The processor system of claim 11 , wherein the access information stored in the storage comprises a command that is issued by a processor and is used to access the non-volatile memory, an address to be accessed, and data.
13. The processor system of claim 11 , wherein the memory controller selects the second mode when the storage has no free space or there is no read command to be executed after a write command stored in the storage.
14. The processor system of claim 11 , wherein the non-volatile memory comprises a plurality of memory areas,
wherein the storage stores the access information in association with a memory area to be accessed among the plurality of memory areas.
15. The processor system of claim 14 , wherein the memory controller processes access information to one memory area stored in the storage and then processes in order access information stored in the storage to other memory areas.
16. The processor system of claim 14 , wherein the memory controller selects the first or the second mode for a memory area to be accessed.
17. The processor system of claim 14 , wherein the memory controller is configured to select the first and the second mode based on the write and read commands stored in the storage.
18. The memory system of claim 1 , wherein the memory controller is configured to select the first and the second mode based on the write and read commands stored in the storage.