# US 12,217,797 B2 · Storage device and operating method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,217,797 B2 - Document ID: US12217797B2 - Status: Granted - Kind: B2 - Application number: 17/806,333 - Filed: 2022-06-10 - Published: 2023-05-04 - Granted: 2025-02-04 - Earliest claimed: 2021-11-03 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Hojin Chun; Jiwon Park - Web page: https://patentgrep.com/patent/US12217797B2 ## CPC - G11C 7/1045: {Read-write mode select circuits} - G11C 14/0018: {whereby the nonvolatile element is an EEPROM element, e.g. a floating gate or metal-nitride-oxide-silicon [MNOS] transistor} - G11C 5/143: {Detection of memory cassette insertion or removal; Continuity checks of supply or ground lines; Detection of supply variations, interruptions or levels (G11C5/148 takes precedence); Switching between alternative supplies (G11C5/141 takes precedence)} - G11C 5/147: {Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops (G11C5/141 takes precedence)} - Y02D 10/00: Energy efficient computing, e.g. low power processors, power management or thermal management - G11C: STATIC STORES (semiconductor memory devices H10B) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A method of operating a storage device includes: sensing an external voltage supplied from a host device; selecting a data transfer mode, where the data transfer mode is either a normal mode or a brown-out mode according to the external voltage; and performing a write operation or a read operation according to the selected mode, wherein: the data transfer mode is selected as the normal mode when the external voltage is within a normal range between a first operation voltage and a second operation voltage, and the data transfer mode is selected as the brown-out mode when the external voltage is within a low power range below the normal range and between the second operation voltage and a power-off detection voltage; and wherein one or more types of input/output operations of the host device are supported in both the normal mode and the brown-out mode. ## Claims ### Claim 1 An operating method of a storage device, the method comprising: sensing an external voltage supplied from a host device; selecting a data transfer mode, wherein the data transfer mode is either a normal mode or a brown-out mode depending upon the external voltage; and performing a write operation or a read operation according to the selected mode, wherein: the data transfer mode is selected as the normal mode when the external voltage is within a normal range between a first operation voltage and a second operation voltage, and the data transfer mode is selected as the brown-out mode when the external voltage is within a low power range below the normal range and between the second operation voltage and a power-off detection voltage, wherein the first operation voltage is a maximum operation voltage of the normal range and the second operation voltage is a minimum operation voltage of the normal range, wherein the storage device supports a write through operation and a nonvolatile memory device (NVM) buffer operation in both the normal mode and the brown-out mode, and wherein an operation speed of the brown-out mode is different than an operation speed of the normal mode. ### Claim 2 (depends on 1) The method of claim 1, wherein: the sensing the external voltage comprises determining whether the external voltage is lower than the second operation voltage. ### Claim 3 (depends on 2) The method of claim 2, wherein: the performing the write operation or the read operation comprises a normal write operation or a normal read operation when the external voltage is within the normal range. ### Claim 4 (depends on 2) The method of claim 2, wherein: the sensing the external voltage further comprises determining whether the external voltage is lower than the power-off detection voltage when the external voltage is lower than the second operation voltage. ### Claim 5 (depends on 4) The method of claim 4, wherein: the performing the write operation or the read operation further comprises performing a specific input/output operation when the external voltage is below the second operation voltage but not lower than the power-off detection voltage. ### Claim 6 (depends on 4) The method of claim 4, further comprising: performing a dumping operation to move data of a buffer memory to a nonvolatile memory device when the external voltage is lower than the power-off detection voltage. ### Claim 7 (depends on 1) The method of claim 1, wherein: a specific input/output operation is performed when the data transfer mode is the brown-out mode. ### Claim 8 (depends on 7) The method of claim 7, wherein: the specific input/output operation includes at least one of: a pre-power-off operation, a write through operation, a buffer size reduction operation, or a performance throttling operation. ### Claim 9 (depends on 1) The method of claim 1, further comprising: performing an operation at limited speed when the data transfer mode is the brown-out mode. ### Claim 10 (depends on 1) The method of claim 1, further comprising: performing a nonvolatile memory buffering operation when the data transfer mode is the brown-out mode. ### Claim 11 A storage device comprising: a current limiter configured to receive an external voltage and to limit current; at least one voltage regulator configured to receive the external voltage output from the current limiter, and to generate a first power supply voltage, a second power supply voltage, and a third power supply voltage; a voltage sensor configured to sense the external voltage; a NAND package configured to receive the first power supply voltage from the at least one voltage regulator, and including a plurality of NAND flash memory devices; a volatile memory device configured to receive the second power supply voltage from the at least one voltage regulator; and a controller configured to receive the third power supply voltage from the at least one voltage regulator and to control the NAND package and the volatile memory device, wherein: the controller receives a voltage information signal from the voltage sensor, and selects a data transfer mode, the data transfer mode being selected as either a normal mode or a brown-out mode in response to the voltage information signal; wherein the normal mode is selected when the external voltage exists within a normal range between a first operation voltage and a second operation voltage, and the brown-out mode is selected when the external voltage exists within a low power range below the normal range and between the second operation voltage and a power-off detection voltage; wherein the first operation voltage is a maximum operation voltage of the normal range and the second operation voltage is a minimum operation voltage of the normal range; wherein the storage device supports a nonvolatile memory device (NVM) buffer operation in both the normal mode and the brown-out mode; and wherein an operation speed of the brown-out mode is different from an operation speed of the normal mode. ### Claim 12 (depends on 11) The storage device of claim 11, further comprising: a power loss prevention circuit configured to monitor the external voltage and to signal the controller to perform a backup operation when the external voltage is cut off or drops below a reference value. ### Claim 13 (depends on 12) The storage device of claim 12, wherein: the power loss prevention circuit transmits a power-off detection signal to the controller in a general purpose input/output (GPIO) interface manner. ### Claim 14 (depends on 11) The storage device of claim 11, further comprising: a nonvolatile memory device configured to perform a buffering function. ### Claim 15 (depends on 14) The storage device of claim 14, wherein: a first buffering operation is performed using the volatile memory device in the normal mode; and a second buffering operation is performed using the nonvolatile memory device in the brown-out mode. ### Claim 16 An operating method of a storage device, the method comprising: monitoring an external voltage; determining whether the external voltage is lower than a minimum operation voltage; when the external voltage is lower than the minimum operation voltage, determining whether the external voltage is lower than a power-off detection voltage; performing an input/output operation according to a first brown-out mode when the external voltage is lower than the minimum operation voltage and higher than the power-off detection voltage; performing an input/output operation according to a normal mode when the external voltage is not lower than the minimum operation voltage; and dumping a firmware when the external voltage is lower than the power-off detection voltage, wherein the input/output operation according to the first brown-out mode includes a write through operation supported in both the normal mode and the brown-out mode, and wherein an operation speed of the brown-out mode is different from an operation speed of the normal mode. ### Claim 17 (depends on 16) The method of claim 16, further comprising: performing a power loss prevention function when the external voltage is cut off or drops below a reference value. ### Claim 18 (depends on 16) The method of claim 16, further comprising: performing an input/output operation according to a second brown-out mode when the external voltage is higher than a maximum operation voltage. ### Claim 19 (depends on 16) The method of claim 16, further comprising: performing an input/output operation according to the normal mode when the external voltage exists between the minimum operation voltage and a maximum operation voltage. ### Claim 20 (depends on 16) The method of claim 16, further comprising: performing a charging operation of an auxiliary power supply included in the storage device according to a second brown-out mode when the external voltage is higher than a maximum operation voltage.