Thus, the CPU could run no faster than its slowest block. By re-partitioning, only the CPU needs to run at the 420 MHz speed, greatly simplifying the VLSI implementation task. The system logic can run either at one-half or full CPU speed, depending on the application requirement. Other clock divide ratios will be supplied in the future to support planned moves to even higher CPU speeds. The introduction of background move is another Lexra innovation.
Embedded applications are data intensive.
About one to three percent of embedded application software comprises instructions for loading and storing data to and from external sources. During this time, the CPU sits idle waiting for the blocked move to complete. The LX4380's solution is a background move, a DMA-like transfer to and from local CPU memory. The transfer can be from any length up to the full size of data memory, and the CPU will continue to execute without stalls while waiting for the data transfer to complete. Once the data is in local memory, the LX4380 has a 64-bit twin register load operation to rapidly transfer data between data memory and the general register file.