Systems and methods of co-simulation utilizing multiple PLDs in a boundary scan chain

Systems and methods of performing co-simulation of a partitioned circuit design using multiple programmable logic devices (PLDs) coupled together to form a boundary scan chain. A host computer is coupled to the scan chain via a programming cable. Resident on the host computer are run-time co-simulation blocks corresponding to blocks from the circuit design, where each block is designated to run on one of the PLDs in the scan chain; a programming cable device driver interfacing with the programming cable; and a proxy component. The proxy component is coupled to all of the run-time co-simulation blocks and the programming cable device driver. Each co-simulation block includes a unique pattern identifier, which is also present in the associated PLD. Using this pattern identifier, data and commands targeted to a specific PLD can be extracted from the scan chain, while ignoring data and commands targeted to other PLDs in the scan chain.