Method and design for dynamic management of descriptors for SGL operation

A controller for a non-volatile semiconductor storage device, comprising:

• a first memory configured to store a plurality of commands received from a host system;
• a second memory;
• and
• a processing system having a back end configured to process active commands and a front end configured to:
• fetch memory descriptors from the host system for each of the plurality of commands stored in the first memory;
• store the memory descriptors for each of the plurality of commands in free descriptor regions of a plurality of descriptor regions in the second memory;
• and
• maintain a dynamic descriptor list in the second memory for each of the plurality of commands, the dynamic descriptor list for each of the plurality of commands comprising occupied descriptor regions of the plurality of descriptor regions in the second memory having associated memory descriptors,
• wherein at least one of the occupied descriptor regions includes multiple memory descriptors and a single pointer to a next occupied descriptor region of the plurality of descriptor regions.

A non-transitory computer readable medium having stored thereon instructions that when executed by a processor cause the processor to perform a method of managing memory descriptors for a plurality of commands to a non-volatile semiconductor storage device, the method comprising:

• requesting memory descriptors from a host system for each of the plurality of commands stored in a first memory;
• storing the memory descriptors for each of the plurality of commands in free descriptor regions of a plurality of descriptor regions in a second memory of the non-volatile semiconductor storage device;
• and
• maintaining a dynamic descriptor list in the second memory for each of the plurality of commands, the dynamic descriptor list for each of the plurality of commands comprising occupied descriptor regions of the plurality of descriptor regions in the second memory having associated memory descriptors,
• wherein at least one of the occupied descriptor regions includes multiple memory descriptors and a single pointer to a next occupied descriptor region of the plurality of descriptor regions.