Memory management method, memory storage device and memory control circuit unit

A memory storage device, comprising:

• a connection interface unit, configured to couple to a host system;
• a rewritable non-volatile memory module, wherein the rewritable non-volatile memory module comprises 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 retrieve at least one physical erasing unit from the physical erasing units as a first physical erasing unit for storing first data corresponding to a write command of a host system to the first physical erasing unit and marking the first physical erasing unit as belonging to a first group, wherein the first data belongs to a first type;
• wherein the memory control circuit unit is further configured to retrieve at least one physical erasing unit from the physical erasing units as a second physical erasing unit for storing second data corresponding to another write command of the host system to the second physical erasing unit and marking the second physical erasing unit as belonging to a second group, wherein the second data belongs to a second type different from the first type;
• wherein the memory control circuit unit is further configured to select a third physical erasing unit from the physical erasing units as an active physical erasing unit and marking the third physical erasing unit as belonging to the first group;
• when a garbage collecting operation is performed on the first physical erasing unit, the memory control circuit unit is further configured to move valid data of the first physical erasing unit to the third physical erasing unit among the physical erasing units if a valid data count of the first physical erasing unit is not less than a first preset value;
• when the garbage collecting operation is performed on the first physical erasing unit, the memory control circuit unit is further configured to move the valid data of the first physical erasing unit to the fourth physical erasing unit if the valid data count of the first physical erasing unit is less than the first preset value;
• when the garbage collecting operation is performed on the second physical erasing unit, the memory control circuit unit is further configured to move valid data of the second physical erasing unit to the fourth physical erasing unit if a valid data count of the second physical erasing unit is less than a second preset value;
• and
• when the garbage collecting operation is performed on the second physical erasing unit, the memory control circuit unit is further configured to move the valid data of the second physical erasing unit to the third physical erasing unit if the valid data count of the second physical erasing unit is not less than the second preset value.

A memory control circuit unit for controlling a rewritable non-volatile memory module comprising a plurality of physical erasing units, the memory control circuit unit comprising:

• a host interface, configured to couple to a host system,
• a memory interface, configured to couple to the rewritable non-volatile memory module;
• and
• a memory management circuit, coupled to the host interface and the memory interface;
• wherein the memory management circuit is configured to retrieve at least one physical erasing unit from the physical erasing units as a first physical erasing unit for storing first data corresponding to a write command of a host system to the first physical erasing unit and marking the first physical erasing unit as belonging to a first group, wherein the first data belongs to a first type;
• wherein the memory management circuit is further configured to retrieve at least one physical erasing unit from the physical erasing units as a second physical erasing unit for storing second data corresponding to another write command of the host system to the second physical erasing unit and marking the second physical erasing unit as belonging to a second group, wherein the second data belongs to a second type different from the first type;
• wherein the memory management circuit is further configured to select a third physical erasing unit from the physical erasing units as an active physical erasing unit and marking the third physical erasing unit as belonging to the first group;
• when a garbage collecting operation is performed on the first physical erasing unit, the memory management circuit is further configured to move valid data of the first physical erasing unit to the third physical erasing unit among the physical erasing units if a valid data count of the first physical erasing unit is not less than a first preset value;
• when the garbage collecting operation is performed on the first physical erasing unit, the memory management circuit is further configured to move the valid data of the first physical erasing unit to the fourth physical erasing unit if the valid data count of the first physical erasing unit is less than the first preset value;
• when the garbage collecting operation is performed on the second physical erasing unit, the memory management circuit is further configured to move valid data of the second physical erasing unit to the fourth physical erasing unit if a valid data count of the second physical erasing unit is less than a second preset value;
• and
• when the garbage collecting operation is performed on the second physical erasing unit, the memory management circuit is further configured to move the valid data of the second physical erasing unit to the third physical erasing unit if the valid data count of the second physical erasing unit is not less than the second preset value.