Agilex™ 7 Hard Processor System Technical Reference Manual

ID 683567
Date 8/13/2024
Public
Document Table of Contents

17.6.2.6.3. Receive Process Suspended

If a new receive frame arrives while the receive process is in the suspend state, the DMA refetches the current descriptor in the Host memory. If the descriptor is now owned by the DMA, the receive process re-enters the run state and starts frame reception. If the descriptor is still owned by the host, by default, the DMA discards the current frame at the top of the MTL RX FIFO buffer and increments the missed frame counter. If more than one frame is stored in the MTL EX FIFO buffer, the process repeats. †

The discarding or flushing of the frame at the top of the MTL EX FIFO buffer can be avoided by disabling Flushing (Bit 24 of Register 6 (Operation Mode Register)). In such conditions, the receive process sets the Receive Buffer Unavailable status and returns to the Suspend state. †