US-12625649-B2 - Volatile memory, system on chip and electronic device comprising the same

US12625649B2US 12625649 B2US12625649 B2US 12625649B2US-12625649-B2

Abstract

A volatile memory device comprises a memory cell array including a plurality of memory cells storing data, and control logic controlling read and write operations for the plurality of memory cells. The control logic is configured to receive a command instructing a self-refresh operation from an external host device, to perform the self-refresh operation in response to the received command, to request the external host device to transfer data stored in the plurality of memory cells in response to a performance time of the self-refresh operation having elapsed a first threshold time, to monitor a read command received from the external host device in response to receiving a notification of self-refresh operation termination and a read command from the external host device, and to enter a power off state in response to the read command not being received for a second threshold time.

Inventors

Sang-Kyu Kang
Ki-Heung Kim
Dong Min Kim
Chang Sik Yoo
Ji Yoon Jeong
Hyun Duk Cho

Assignees

SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20240815
Priority Date: 20240109

Claims (20)

1 . A volatile memory device comprising: a memory cell array including a plurality of memory cells configured to store data; and control logic configured to control read and write operations for the plurality of memory cells, wherein the control logic is configured to receive a command instructing a self-refresh operation from an external host device, perform the self-refresh operation in response to the received command, request the external host device to issue an initial read command to transfer data stored in the plurality of memory cells in response to a performance time of the self-refresh operation having elapsed a first threshold time, monitor for an additional read command received from the external host device in response to receiving both a notification of self-refresh operation termination and the initial read command from the external host device, and enter a power off state in response to the additional read command not being received after a second threshold time has elapsed.
2 . The volatile memory device of claim 1 , further comprising: a time setting register configured to store the first threshold time; and a self-refresh timer configured to monitor whether the performance time of the self-refresh operation has elapsed the first threshold time based on the first threshold time in the time setting register, and provide a first control signal to the control logic in response to the performance time of the self-refresh operation having elapsed the first threshold time.
3 . The volatile memory device of claim 2 , further comprising: a command timer configured to monitor for the additional read command provided to the control logic from the external host device, and provide a second control signal to the control logic in response to the additional read command not being received for the second threshold time.
4 . The volatile memory device of claim 3 , wherein the second threshold time is shorter than the first threshold time.
5 . The volatile memory device of claim 2 , wherein the first threshold time is provided from the external host device upon the volatile memory device being initialized.
6 . The volatile memory device of claim 1 , wherein the control logic is configured to request the external host device to transfer data stored in the plurality of memory cells by transmitting a flag signal to the external host device.
7 . The volatile memory device of claim 6 , wherein the control logic is configured to switch the volatile memory device to an active mode in response to the performance time of the self-refresh operation having elapsed the first threshold time, and request the external host device to transfer data stored in the plurality of memory cells by maintaining a first data port signal transmitted to the external host device at a first logic state for a 64BL (Burst length).
8 . The volatile memory device of claim 1 , wherein the control logic is configured to store information in a mode register indicating that the performance time of the self-refresh operation has elapsed the first threshold time in response to the performance time of the self-refresh operation having elapsed the first threshold time, and request the external host device to transfer data stored in the plurality of memory cells by having the external host device check the stored information in the mode register.
9 . The volatile memory device of claim 1 , wherein the control logic continues to perform the self-refresh operation in response to not receiving a notification of self-refresh operation termination from the external host device.
10 . The volatile memory device of claim 1 , wherein the volatile memory device includes a DRAM (Dynamic Random Access Memory).
11 . A System on Chip (SoC) comprising: a first interface configured to communicate with a volatile memory device; a second interface configured to communicate with a non-volatile memory device; and a controller configured to control the first and second interfaces, wherein the controller is configured to transmit a command to the volatile memory device instructing to perform a self-refresh operation, receive a request from the volatile memory device to transfer data stored in the volatile memory device to the non-volatile memory device, determine whether the volatile memory device has performed the self-refresh operation in response to a vehicle being powered off, upon determining that the volatile memory device has performed the self-refresh operation in response to the vehicle being powered off, transmit a read command to the volatile memory device in response to the request, upon determining that the volatile memory device has not performed the self-refresh operation in response to the vehicle being powered off, transmit a command instructing the self-refresh operation to the volatile memory device in response to the request, the controller is further configured to receive data corresponding to the read command from the volatile memory device, store the received data in the non-volatile memory device, receive a control signal from a sensor, and power on the volatile memory device in response to the control signal.
12 . The SoC) of claim 11 , wherein the controller is further configured to transmit a first threshold time to the volatile memory device upon the volatile memory device being initialized, and receive the request from the volatile memory device, after transmitting the command instructing the self-refresh operation to the volatile memory device and the first threshold time has elapsed.
13 . The SoC of claim 11 , wherein the controller is configured to receive the control signal from the sensor before the vehicle is powered on.
14 . The SoC of claim 11 , wherein the controller is configured to receive the request via a flag signal from the volatile memory device.
15 . The SoC of claim 14 , wherein the flag signal comprises a signal that a first data port signal is maintained at a first logic level for a 64BL (Burst Length).
16 . The SoC of claim 11 , wherein the controller is configured to receive the request by checking information stored in a mode register of the volatile memory device.
17 . An electronic device configured to be included in a vehicle, the electronic device comprising: a volatile memory device configured to store first data used for an operation of the vehicle; a non-volatile memory device configured to store second data used for the operation of the vehicle; a sensor configured to output a control signal in response to receiving a detection signal from at least one of a door, a seat, and a seat belt of the vehicle; and, a System on Chip (SoC) configured to power on the volatile memory device in response to the control signal received from the sensor, and to control the volatile memory device and the non-volatile memory device, wherein the volatile memory device is configured to receive a command instructing a self-refresh operation from the SoC, perform the self-refresh operation in response the received command, request the SoC to transfer data stored in the volatile memory device to the non-volatile memory device in response a performance time of the self-refresh operation having elapsed a first threshold time, wherein the SoC is configured to, upon determining that the volatile memory device has performed the self-refresh operation in response to the vehicle being powered off, in response to the request, transmit a read command to the volatile memory device, receive data corresponding to the read command from the volatile memory device, and store the received data in the non-volatile memory device, and upon determining that the volatile memory device has not performed the self-refresh operation in response to the vehicle being powered off, in response to the request, transmit a command instructing the self-refresh operation the volatile memory device.
18 . The electronic device of claim 17 , wherein the volatile memory device comprises a time setting register configured to store the first threshold time; and a self-refresh timer configured to monitor whether the performance time of the self-refresh operation has elapsed the first threshold time based on the first threshold time of the time setting register.
19 . The electronic device of claim 18 , wherein the SoC is configured to provide the first threshold time to the volatile memory upon the volatile memory device being initialized.
20 . The electronic device of claim 19 , wherein the volatile memory device further comprises a command timer configured to monitor the read command received from the SoC and to monitor whether the read command is not received for a second threshold time.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priorities from Korean Patent Application No. 10-2024-0003344 filed on Jan. 9, 2024 and Korean Patent Application No 10-2024-0026623 filed on Feb. 23, 2024 in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. 119, the contents of which in its entirety are herein incorporated by reference. BACKGROUND Various example embodiments relate to one or more of a volatile memory, a SoC, and an electronic device comprising the same. Electronic devices may be installed in a vehicle to control and provide information of the vehicle. In an automotive system applied to vehicles, such as cars, trucks, sport-utility vehicles, etc., when the power of the vehicle is turned off, an ECU (Electronic Control Unit) for controlling the vehicle is also powered off. In this case, volatile memory, such as DRAM (Dynamic Random Access Memory), which is necessary or used for the operation of the ECU, performs a self-refresh operation to maintain the data stored in it even when the ECU is powered off. The current consumption due to this self-refresh operation increases with higher capacities of volatile memory. Therefore, research is needed or desired to improve this issue. SUMMARY Various example embodiments may provide a volatile memory device, a SoC (System on Chip), and/or an electronic device that can reduce operation power. According to some example embodiments, there is provided a volatile memory device comprising a memory cell array including a plurality of memory cells configured to store data; and control logic configured to control read and write operations for the plurality of memory cells. The control logic is configured to receive a command instructing a self-refresh operation from an external host device, perform the self-refresh operation in response to the received command, request the external host device to transfer data stored in the plurality of memory cells in response to a performance time of the self-refresh operation having elapsed a first threshold time, monitor a read command received from the external host device in response to receiving a notification of self-refresh operation termination and a read command from the external host device, enter a power off state in response to the read command not being received for a second threshold time. Alternatively, or additionally, according to some example embodiments, there is provided a SoC (System on Chip) comprising a first interface configured to communicate with a volatile memory device; a second interface configured to communicate with a non-volatile memory device; and a controller configured to control the first and second interfaces. The controller is configured to transmit a command to the volatile memory device instructing to perform a self-refresh operation, receive a request from the volatile memory device to transfer data stored in the volatile memory device to the non-volatile memory device, determine whether the volatile memory device has performed the self-refresh operation in response to a vehicle being powered off, upon determining that the volatile memory device has performed the self-refresh operation in response to the vehicle being powered off, transmit a read command to the volatile memory device in response to the request, upon determining that the volatile memory device has not performed the self-refresh operation in response to the vehicle being powered off, transmit a command instructing the self-refresh operation to the volatile memory device in response to the request, receive data corresponding to the read command from the volatile memory device, store the received data in the non-volatile memory device, receive a control signal from a sensor, and power on the volatile memory device in response to the control signal. Alternatively or additionally according to various example embodiments, there is provided an electronic device configured to be included in a vehicle, the electronic device comprising a volatile memory device configured to store first data used for an operation of the vehicle; a non-volatile memory device configured to store second data used for the operation of the vehicle; a sensor configured to output a control signal in response to receiving a detection signal from at least one of a door, a seat, and a seat belt of the vehicle; and a System on Chip (SoC) configured to power on the volatile memory device in response to the control signal received from the sensor, and to control the volatile memory device and the non-volatile memory device. The volatile memory device is configured to receive a command instructing a self-refresh operation from the SoC, perform the self-refresh operation in response the received command, request the SoC to transfer data stored in the volatile memory device to the non-volatile memory device in response a performance time of the self-refresh operation having elapsed a first threshold tim