System and method for removing retired entries from a command buffer using tag information

A system comprising:

• one or more slave devices coupled to a bus,
• wherein each slave device includes a processor and a slave command buffer, and
• wherein the processor is configured to receive a read command, and
• when there are one or more available locations in the command buffer,
• store the read command in one of the available locations,
• assign a slave tag (s-tag) value to the read command, wherein the s-tag value comprises an index to the location in the command buffer in which the read command is stored, and
• transmit a reply to the read command, wherein the reply includes an acknowledgment and the s-tag value.

A bus agent comprising:

• a processor;
• a master command buffer;
• and
• a slave command buffer;
• wherein the bus agent is configured to act as either a master or a slave in a read transaction;
• wherein when the bus agent acts as a slave, the processor is configured to
• receive a read command and a master tag (m-tag) value associated with the read command, and
• when there are one or more available locations in a corresponding slave command buffer,
• store the read command in one of the available locations,
• assign a slave tag (s-tag) value to the read command, wherein the s-tag value comprises an index to the location in the slave command buffer in which the read command is stored, and
• transmit a reply to the write command including an acknowledgment, the m-tag value and the s-tag value.