US Patent 7707019 Command buffering for hardware co-simulation

A method of co-simulation involving a high level modeling system and an integrated circuit such as, e.g., a programmable logic device (PLD) can include, when writing to at least one input port of the PLD, storing a plurality of commands from a co-simulation engine within a command buffer and, responsive to a send condition, sending the plurality of commands to the PLD as a single transaction. When reading from at least one output port of the PLD, selectively reading from a cache external to the PLD or a memory of the PLD according to a state of cache coherency.