Row-wise Accumulator Implementation

This page provides the row-wise accumulator implementation details. The following figure shows the row-wise accumulator logic.

• There are three input streams, namely the column vector value stream, the NNZ value stream and the NNZ row indices stream.
• Each stream contains multiple entries being processed in parallel. For example, there are 4 entries being processed in parallel as shown in the figure.
• The number of parallel entries can be configured at the compile time by SPARSE_parEntries.
• The xBarRow logic, illustrated by the formRowEntry, split and merge modules in the figure, carries out the multiplication of the column value and the NNZ value, and distributes the results and their corresponding row indices to the accumulator logic implemented by the rowMemAcc logic.
• There are multiple on-chip memory blocks in each rowMemAcc logic to store the accumulation results and remove the floating point accumulation bubbles.
• Once the accumulation operation is finished, each rowMemAcc module will read out the data in the on-chip memory and send them to rowAgg module to be merged together and written to the device memory, for example, HBM.