Visible to Intel only — GUID: lro1402197146382
Ixiasoft
Visible to Intel only — GUID: lro1402197146382
Ixiasoft
31.1. Core Overview
In a processor subsystem, data transfers between two memory spaces can happen frequently. In order to offload the processor from moving data around a system, a Direct Memory Access (DMA) engine is introduced to perform this function instead. The Modular Scatter-Gather DMA (mSGDMA) is capable of performing data movement operations with preloaded instructions, called descriptors. Multiple descriptors with different transfer sizes, and source and destination addresses have the option to trigger interrupts.
The mSGDMA core has a modular design that facilitates easy integration with the FPGA fabric. The core consists of a dispatcher block with optional read host and write host blocks. The descriptor block receives and decodes the descriptor, and dispatches instructions to the read host and write host blocks for further operation. The block is also configured to transfer additional information to the host. In this context, the read host block reads data through its Avalon® -MM host interface, and channels it into the Avalon® -ST source interface, based on instruction given by the dispatcher block. Conversely, the write host block receives data from its Avalon® -ST sink interface and writes it to the destination address via its Avalon® -MM host interface.