An online parallel CRC32 realization for Hybrid Memory Cube protocol

Abstract

Hybrid Memory Cube (HMC) is a revolutionary standard in DRAM architecture based on 3D integration. It provides marvelous concurrency and reduced latency. HMC uses CRC32 for data integrity, but conventional Serial CRC calculation is very slow and has long latencies, here we propose three methods to implement parallel CRC to be very fast. The first method uses symbolic toolbox in MATLAB to generate the final equations of the CRC, and then these equations are exported to VERILOG so that we are able to calculate it in only one clock cycle. The second method is depending on using an existing tool that can generate parallel CRC but this tool has a limitation on the input data width as it is less than the maximum allowed data width in HMC which is 1152 bits, so we were able to find a work around method that enable us to calculate CRC32 for large data widthwith this tool. The third method is based on using the polynomial mathematics for CRC, as the CRC can be calculated using long division method. Method 1 latency is one clock cycle, Method 2 latency is 2 clock cycles, and method 3 latency is 37 clock cycles compared to serial CRC which latency is 1152 clock cycles.