1. A method of operating an asynchronous processing system comprising an asynchronous scalar processor and an asynchronous vector processor coupled to the asynchronous scalar processor, the asynchronous vector processor comprising a plurality of parallel asynchronous vector execution units (VXU), the method comprising: performing processing functions on input data at the asynchronous scalar processor and sending a very long instruction word (VLIW) to the asynchronous vector processor; generating, by the parallel asynchronous VXU, an instruction execution result corresponding to the VLIW; storing, in a register file, the instruction execution result generated by the parallel asynchronous VXU; storing, in a history table, a time at which a register within the register file was last modified; and detecting a data dependency via the history table based on the time at which the register within the register file was last modified.