Buffer management for data transfers between a host device and a storage medium

A data transfer system for transferring data between a host device and a storage medium, comprising:

• a host interface that receives from the host device a command to transfer data between the host device and the storage medium;
• a buffer that temporarily stores data that is transferred between the host device and the storage medium;
• a first register that stores a value for tracking a number of data units that have been transferred into the buffer but that have not yet been transferred out of the buffer;
• a second register that stores a value for incrementing a value contained in the first register;
• and
• a third register that stores a value for decrementing a value contained in the first register.

A method for transferring data between a host device and a storage medium, comprising:

• receiving from the host device a command to transfer data between the host device and the storage medium;
• storing in a first register a value for determining a buffer's fullness;
• incrementing a value contained in the first register by a value contained in a second register;
• and
• decrementing a value contained in the first register by a value contained in a third register.

An application specific integrated circuit (ASIC) for transferring data between a host device and a storage medium, comprising:

• a buffer that temporarily stores data that is transferred between the host device and the storage medium;
• a first register that stores a value for determining the buffer's fullness;
• a second register that stores a value for incrementing a value contained in the first register;
• and
• a third register that stores a value for decrementing a value contained in the first register.