Operation method of universal flash storage host and operation method of universal flash storage system

1. An operation method of a universal flash storage (UFS) host configured to control a UFS device, the method comprising:

configuring a turbo write buffer of the UFS device;

sending a first query request UFS protocol information unit (UPIU) including reconfiguration information about the turbo write buffer to the UFS device, during driving the UFS device, the reconfiguration information including a turbo write buffer capacity adjustment factor of the turbo write buffer; and

receiving a first response UPIU associated with the first query request UPIU from the UFS device, wherein,

the first query request UPIU is a request that causes a size of the turbo write buffer of the UFS device to be changed from a first size to a second size different from the first size,

each of memory cells corresponding to the turbo write buffer is configured to store “N” bits, where “N” is a natural number, and

the turbo write buffer capacity adjustment factor indicates information about “N”.

2. The method of claim 1 , wherein the turbo write buffer is not identified by the UFS host.

3. The method of claim 1 , wherein the reconfiguration information includes information about a size of the turbo write buffer.

4. The method of claim 3 , wherein the first query request UPIU includes information about a current turbo write buffer size field of attributes of the UFS device.

5. The method of claim 1 ,

wherein the reconfiguration information includes information about a mode of the turbo write buffer, and

wherein the mode is one of a user capacity reduction mode, a no user capacity reduction mode, and a partial-reduction mode.

6. The method of claim 1 ,

wherein the reconfiguration information includes information about a type of the turbo write buffer, and

wherein the type is one of a logical unit dedicated buffer type and a shared buffer type.

7. The method of claim 1 , wherein the configuring of the turbo write buffer includes:

reading a device descriptor and a geometry descriptor of the UFS device;

determining information about a type, a mode, and a size of the turbo write buffer based on the device descriptor and the geometry descriptor;

sending a second query request UPIU to the UFS device based on the determined information; and

receiving a second response UPIU corresponding to the second query request UPIU from the UFS device,

wherein the second query request UPIU is a request for setting fields of a configuration descriptor of the UFS device.

8. The method of claim 7 , wherein, the second query request UPIU is a request that causes a configuration descriptor lock field of the configuration descriptor of the UFS device to be set.

9. The method of claim 8 , further comprising:

before sending the first query request UPIU to the UFS device, sending a third query request UPIU including a field value for unlocking the configuration descriptor of the UFS device to the UFS device; and

receiving a third response UPIU associated with the third query request UPIU,

wherein, after the third response UPIU is received, the first query request UPIU is sent to the UFS device.

10. The method of claim 9 , further comprising:

after the first response UPIU is received, sending a fourth query request UPIU including a field value for setting a lock of the configuration descriptor of the UFS device to the UFS device; and

receiving a fourth response UPIU associated with the fourth query request UPIU.

11. The method of claim 1 , further comprising:

setting a turbo write buffer enable field of a FLAG of the UFS device; and

sending a write command and write data to the UFS device,

wherein, when the turbo write buffer enable field is set, the write data are first written in the turbo write buffer.

12. An operation method of a universal flash storage (UFS) host configured to control a UFS device, the method comprising:

configuring a turbo write buffer at the UFS device;

locking a configuration description of the UFS device;

unlocking the configuration description of the UFS device; and

reconfiguring the turbo write buffer during driving the UFS device without a reset or an initialization of the UFS device, wherein,

each of memory cells of a first physical storage space corresponding to the turbo write buffer from among physical storage spaces of the UFS device is configured to store N bits,

a second physical storage space corresponding to user storage from among the physical storage spaces of the UFS device is configured to store M bits,

N is a natural number, and

M is a natural number more than the N.

13. The method of claim 12 , further comprising:

before configuring the turbo write buffer,

sending a first query request UFS protocol information unit (UPIU) for setting a gathering interval for hint information to the UFS device;

receiving a first response UPIU corresponding to the first query request UPIU from the UFS device;

sending a second query request UPIU for reading the hint information to the UFS device; and

receiving a second response UPIU including the hint information from the UFS device.

14. The method of claim 13 , wherein the reconfiguring of the turbo write buffer during the driving the UFS device includes:

determining reconfiguration information including at least one of a mode, a type, and a size of the turbo write buffer, based on the hint information;

sending a third query request UPIU including the reconfiguration information to the UFS device; and

receiving a third response UPIU corresponding to the third query request UPIU.

15. An operation method of a universal flash storage (UFS) system including a UFS device and a UFS host, the method comprising:

configuring, by the UFS host, a turbo write buffer of the UFS device;

sending, by the UFS host, a write command and write data to the UFS device;

writing, by the UFS device, the write data in the turbo write buffer and sending a response to the write command to the UFS host;

flushing, by the UFS device, the write data stored in the turbo write buffer to user storage; and

reconfiguring, by the UFS host, the turbo write buffer by changing at least one of a mode, a type, and a size of the turbo write buffer of the UFS device, the reconfiguring of the turbo write buffer including,

unlocking, by the UFS host, a configuration descriptor of the UFS device,

changing, by the UFS host, a first field of the configuration descriptor of the UFS device, and

locking, by the UFS host, the configuration descriptor of the UFS device.

16. The method of claim 15 , wherein the first field includes information about at least one of the mode, the type, and the size of the turbo write buffer.

17. The method of claim 15 , wherein the write command is included in a command UPIU, and a GROUP NUMBER of the command UPIU has a preset value.

18. The method of claim 15 , wherein the mode of the turbo write buffer is one of a user capacity reduction mode, a no user capacity reduction mode, and a partial-reduction mode.