Methods and Apparatus for Issuing Commands on a Bus

An apparatus for issuing a command, comprising:

• a bus;
• and
• command pipeline logic coupled to the bus and including a dependency matrix adapted to store data indicating whether a functional memory command received by the command pipeline logic has an ordering dependency on one or more functional memory commands previously received by the command pipeline logic;
• wherein the command pipeline logic is adapted to:
• receive a first functional memory command;
• receive a command to force the command pipeline logic to execute functional memory commands in order;
• receive a second functional memory command;
• and
• employ the dependency matrix to indicate the second functional memory command has an ordering dependency on the first functional memory command whether or not the second functional memory command actually has an ordering dependency on the first functional memory command.

A system for issuing a command, comprising:

• a first processor;
• and
• a second processor coupled to the first processor and adapted to communicate with the first processor;
• wherein the first processor includes an apparatus for issuing a command, comprising:
• a bus;
• and
• command pipeline logic coupled to the bus and including a dependency matrix adapted to store data indicating whether a functional memory command received by the command pipeline logic has an ordering dependency on one or more functional memory commands previously received by the command pipeline logic;
• wherein the apparatus is adapted to:
• receive a first functional memory command in the system;
• receive a command to force the system to execute functional memory commands in order;
• receive a second functional memory command in the system;
• and
• employ the dependency matrix to indicate the second functional memory command requires access to the same address as the first functional memory command whether or not the second functional memory command actually has an ordering dependency on the first functional memory command.