Reporting flash memory operating voltages
Apparatus and associated systems, methods and computer program products relate to using information stored in a flash memory to adjust the operating voltage supplied to the flash memory. The voltage information indicates a minimum operating voltage at which to operate the flash memory device. In general, operating a flash memory device near a minimal operating voltage may substantially minimize power consumption. The minimum operating voltage for individual flash memory devices may vary from IC to IC, by manufacturing lot, and by manufacturer. In a product, the minimum operating voltage for a particular flash memory may be determined, for example, by a controller built-in to a flash memory reporting (automatically or in response to a query) the minimum operating voltage (e.g., 2.5 V, 3.15 V) to a memory controller or microprocessor. The stored voltage information may further include information to adjust the operating voltage based on temperature.
1. A flash memory device, comprising:
a plurality of memory cells for storing data that may be accessed during a read operation;
a voltage input for connection to an output of a voltage-regulated power supply;
a register containing information about an operating voltage to supply from the voltage-regulated power supply to the voltage input when the flash memory device is performing a read operation of one or more of the memory cells, wherein the information comprises a minimum operating voltage to supply to the voltage input when the flash memory device is performing a read operation of one or more memory cells; and
a processor configured to determine the operating voltage to supply from the voltage-regulated power supply to the voltage input for performing the read operation of the one or more memory cells based upon a mode of operation of the flash memory device and the information contained in the register regarding the minimum operating voltage, wherein the mode of operation of the flash memory device specifies a performance threshold for operation of the flash memory device.
2. The flash memory device of claim 1 , wherein the information about the operating voltage is programmed into the register during manufacture of the flash memory device.
3. The flash memory device of claim 1 , wherein some of the memory cells comprise NAND memory cells.
4. The flash memory device of claim 3 , wherein some of the memory cells comprise NOR memory cells.
5. The flash memory device of claim 3 , wherein the voltage-regulated power supply comprises a switched-mode power supply.
6. A method of supplying power to a flash memory device, the method comprising:
receiving information about an operating voltage to supply to a voltage input of a flash memory device that is performing a read operation, wherein the information comprises a minimum operating voltage to supply to the voltage input when the flash memory device is performing a read operation of one or more memory cells;
receiving information about a mode of operation of the flash memory device, wherein the mode of operation of the flash memory device specifies a performance threshold for operation of the flash memory device;
receiving a command to read data that is stored in a flash memory device;
setting an output voltage coupled to a voltage supply input of the flash memory device based upon the received operating voltage information and the received mode of operation information; and
executing the command to read the data.
7. The method of claim 6 , further comprising sending a command to the flash memory device to access information containing the operating voltage information.
8. The method of claim 6 , wherein setting an output voltage coupled to a voltage supply input of the flash memory device according to the received operating voltage information comprises sending a signal to a voltage-regulated power supply.
9. The method of claim 8 , wherein the voltage-regulated power supply comprises a switched-mode power supply.
10. The method of claim 6 , wherein the operating voltage information is determined during manufacture of the flash memory device.
11. The method of claim 10 , wherein the operating voltage information is programmed into a register of the flash memory device during manufacture of the flash memory device.
12. The method of claim 6 , wherein the information about the operating voltage is programmed into a register of the flash memory device during manufacture of the flash memory device.
13. The method of claim 6 , wherein the command to read data is received over a bus in substantial compliance with an advanced technology attachment (ATA) standard.
14. The method of claim 6 , wherein the command to read data is received over a bus in substantial compliance with a serial advanced technology attachment (SATA) standard.
15. A computer program product tangibly embodied in a machine-readable storage device, the computer program product containing instructions that, when executed, cause a processor to perform operations to supply substantially a preset voltage to a flash memory device when processing a read command, the operations comprising:
receive a request to read data stored on a flash memory device;
receive voltage information stored in a non-volatile memory location in the flash memory device, the voltage information indicating a minimum operating voltage of the flash memory device to supply to a voltage input of the flash memory device that is performing a read operation;
receive information about a mode of operation of the flash memory device, wherein the mode of operation of the flash memory device specifies a performance threshold for operation of the flash memory device;
send a signal to a voltage regulator to supply a voltage to the flash memory device, wherein the supplied voltage is determined based upon the received voltage information and the received mode of operation information; and
read the flash memory device according to the read request.
16. The computer program product of claim 15 , wherein the stored voltage information comprises information stored into a register of the flash memory device during manufacture of the flash memory device.
17. A system for operating at least one flash memory device, the system comprising:
means for reporting information about a mode of operation of the flash memory device, wherein the mode of operation of the flash memory device specifies a performance threshold for operation of the flash memory device;
means for reporting voltage information stored in the flash memory device, wherein the information comprises a minimum operating voltage to supply to a voltage input when the flash memory device is performing a read operation of one or more memory cells; and
a controllable voltage regulator having an output node regulated to a voltage based on the reported voltage information and the mode of operation information, the output node to supply operating power to a load that comprises the flash memory device.
18. The system of claim 17 , further comprising means for reporting voltage information stored in at least one additional flash memory device.
19. The system of claim 18 wherein the output node is regulated to a voltage at least as high as the least of the reported voltages represented by the voltage information stored in any of the flash memory devices.