Scheme for finding and checking whether page units in one block are empty pages by using flash memory device based on smaller search range

A method of a flash memory device to be used in a storage device and coupled to a flash memory controller of the storage device through a specific communication interface, and the method comprises:

• providing an input/output (I/O) control circuit, coupled to the flash memory controller through the specific communication interface;
• providing a command register, coupled to the I/O control circuit, for buffering command information sent from the flash memory controller and transmitted through the I/O control circuit;
• providing an address register, coupled to the I/O control circuit, for buffering address information sent from the flash memory controller and transmitted through the I/O control circuit;
• providing a memory cell array, at least having a first plane and a second plane which is different from the first plane;
• providing at least one address decoder, coupled to the memory cell array;
• providing at least one address decoder;
• providing a status register, coupled to the I/O control circuit;
• controlling the at least one address decoder to read out a temporary page position stored in a storage space of the memory cell array;
• controlling the I/O control circuit transmitting the temporary page position to the flash memory controller via the specific communication interface;
• and
• controlling the at least one address decoder to read out more page data of multiple page units from a specific block in the memory cell array to determine whether the multiple page units are empty pages in response to a specific boundary check command signal or a specific boundary check set-feature signal sent from the flash memory controller via the specific communication interface;
• wherein the temporary page position is used as a start page address by the flash memory controller and is carried by the specific boundary check command signal or the specific boundary check set-feature signal sent from the flash memory controller.

A flash memory controller to be used in a storage device and coupled to a flash memory device of the storage device through a specific communication interface, comprising:

• an input/output (I/O) circuit, coupled to the flash memory device through the specific communication interface, for sending commands and data between the flash memory device and a processor;
• and
• the processor, coupled to the I/O circuit, configure for:
• controlling the I/O circuit to make the flash memory device read and transmit a temporary page position stored in a storage space of a memory cell array of the flash memory device to the flash memory controller;
• and
• controlling the I/O circuit sending a specific boundary check command signal or a specific boundary check set-feature signal via the specific communication interface to the flash memory device, to make the flash memory device read out more page data of multiple page units from a specific block in the memory cell array and to make the flash memory device determine whether the multiple page units are empty pages;
• wherein the temporary page position is used as a start page address by the processor and is carried by the specific boundary check command signal or the specific boundary check set-feature signal sent from the flash memory controller.