Garbage collection while maintaining predetermined writing speed

A memory storage device, comprising:

• a connection interface unit, coupled to a host system;
• a rewritable non-volatile memory module, comprising a plurality of physical erasing units;
• and
• a memory control circuit unit, coupled to the connection interface unit and the rewritable non-volatile memory module,
• wherein the memory control circuit unit is configured to receive first data from the host system,
• wherein the memory control circuit unit is further configured to detect a total number of first type physical erasing units among the physical erasing units, wherein each of the physical erasing units belonging to the first type physical erasing unit does not store valid data,
• wherein the memory control circuit unit is further configured to instruct to execute a first procedure if the total number of the first type physical erasing units is smaller than a first threshold value,
• wherein the memory control circuit unit is further configured to instruct to stop the first procedure if the total number of the first type physical erasing units is greater than a second threshold value, wherein the second threshold value is greater than the first threshold value,
• wherein the memory control circuit unit, in the first procedure, is configured to:
• receive second data from the rewritable non-volatile memory module;
• temporarily store the first data and the second data;
• and
• dynamically determine a writing rule according to a valid data storage status of the physical erasing units during a period of executing the first procedure, and store the first data and the second data into the rewritable non-volatile memory module according to the writing rule, such that a writing speed of the rewritable non-volatile memory module corresponding to the first data in the first procedure is not lower than a predetermined value.

A memory control circuit unit, adapted to control a rewritable non-volatile memory module, wherein the rewritable non-volatile memory module comprises a plurality of physical erasing units, the memory control circuit unit comprises:

• a host interface, coupled to a host system;
• a memory interface, coupled to the rewritable non-volatile memory module;
• a buffer memory;
• and
• a memory management circuit, coupled to the host interface, the memory interface and the buffer memory,
• wherein the memory management circuit is configured to receive first data from the host system,
• wherein the memory management circuit is further configured to detect a total number of first type physical erasing units among the physical erasing units, wherein each of the physical erasing units belonging to the first type physical erasing unit does not store valid data,
• wherein the memory management circuit is further configured to instruct to execute a first procedure if the total number of the first type physical erasing units is smaller than a first threshold value,
• wherein the memory management circuit is further configured to instruct to stop the first procedure if the total number of the first type physical erasing units is greater than a second threshold value, wherein the second threshold value is greater than the first threshold value,
• wherein the memory management circuit, in the first procedure, is configured to:
• receive second data from the rewritable non-volatile memory module;
• temporarily store the first data and the second data to the buffer memory;
• and
• dynamically determine a writing rule according to a valid data storage status of the physical erasing units, and store the first data and the second data into the rewritable non-volatile memory module according to the writing rule, such that a writing speed of the rewritable non-volatile memory module corresponding to the first data in the first procedure is not lower than a predetermined value.