Patent ID: 7634591

Claim:
A method of tracking dependencies of commands within one or more command queues of a processor, comprising: (a) generating dependency information identifying whether a first command issued by the processor received into the command queues depends on other commands issued by the processor previously received in the command queues, wherein the first command depends on another command if an address targeted by the first command is the same as an address targeted by one or more commands previously received in the command queues; (b) storing the command dependency information in a command dependency scoreboard, wherein the command dependency scoreboard is a two dimensional grid, with rows or columns along one axis corresponding to independent commands and columns or rows along another axis corresponding to dependent commands, and information indicating dependency between the first command and a second command is stored at an intersection of a row or column corresponding to the first command and a column or row corresponding to the second command; (c) preventing issuance of the first command if the dependency information in the command dependency scoreboard indicates the first command is dependent on other commands in the command queues; and (d) updating the command dependency information stored in the command dependency scoreboard after commands issued from the command queues have finished executing.