Visible to Intel only — GUID: iga1401396179979
Ixiasoft
Visible to Intel only — GUID: iga1401396179979
Ixiasoft
2.3.2. Operation
The core receives data on its in interface ( Avalon® -ST sink) and stores the data in the allocated memory segments. If a packet contains any error (in_error signal is asserted), the core drops the packet.
When the core receives a request on its request interface ( Avalon® -MM agent), it forwards the requested data to its out interface ( Avalon® -ST source) only when it has received a full packet on its in interface. If the core has not received a full packet or has no data for the requested channel, it deasserts the valid signal on its out interface to indicate that data is not available for the channel. The output latency is three and only one word of data can be requested at a time.
When the Avalon® -MM request interface is not in use, the request_write signal is kept asserted and the request_address signal is set to 0. Hence, if you configure the core to support more than one channel, you must also ensure that the Use request parameter is turned on. Otherwise, only channel 0 is accessible.
You can configure almost-full thresholds to manage FIFO overflow. The current threshold status for each channel is available from the core's Avalon® -ST status interfaces in a round-robin fashion. For example, if the threshold status for channel 0 is available on the interface in clock cycle n, the threshold status for channel 1 is available in clock cycle n+1 and so forth.