Butterfly Network Load Return Alignment for Cache Stall Reduction

The patent pre-calculates control signals for the butterfly network multiplexers using simple combinatorial logic based on input and output port indices. Instead of using complex control circuits to dynamically determine multiplexer settings, the control signals are pre-determined by the formula: control_signal = (output_port_index - input_port_index) / 2. This preliminary calculation approach simplifies the control circuitry while maintaining full data transformation capability.

The patent changes the control approach from complex dynamic control to simple parameter-based control. By using the port indices as parameters in a straightforward mathematical relationship, the control signals become predictable and easily generated, reducing the complexity of control circuits while preserving the network's transformation capabilities.

The patent segments the memory access function from the main processor by introducing a dedicated streaming engine. This separate component handles all memory access operations, allowing the processor to focus on data processing. The streaming engine includes dedicated address generation units and buffer memory, creating a specialized subsystem that improves memory access efficiency without increasing the complexity of the main processor.

The patent introduces a buffer memory as an intermediary between the streaming engine and the main memory system. This buffer acts as a mediator that decouples memory access operations from processing operations, allowing the processor to continue working while data is being loaded or stored. The buffer memory absorbs the complexity of address generation and timing coordination, improving overall system efficiency.

The patent merges the data loading and processing functions into a unified streaming engine architecture. The streaming engine combines address generation, memory access, buffer management, and data formatting in a single integrated subsystem. This merging eliminates the need for separate memory access operations that would cause cache misses, as data is directly streamed from memory through the buffer to the processor in a continuous flow, reducing processing delays.

The streaming engine performs preliminary actions by pre-loading data into the buffer memory before the processor needs it. The address generation unit continuously generates addresses and loads data into the buffer in advance, so that when the processor requests data, it is already available. This preliminary data preparation eliminates cache miss stalls and ensures continuous processing.