Programmable Logic (PL) - 2021.2 English

Versal ACAP AI Engine Programming Environment User Guide (UG1076)

Document ID
UG1076
Release Date
2021-12-17
Version
2021.2 English

The PL table, as shown in the following figure, provides detailed information about the PLIO connections to the ADF graph. For example, in this figure, there are four PLIO objects associated with the graph. The name of the PLIO connection, the width of the PLIO data connection, and the simulation test bench file associated with each PLIO connection is provided in the example.

PLIO *in0 = new PLIO("DataIn1", adf::plio_32_bits,"data/input.txt");
PLIO *ai_to_pl = new PLIO("clip_in",adf::plio_32_bits, "data/output.txt"); 
PLIO *pl_to_ai = new PLIO("clip_out", adf::plio_32_bits,"data/input2.txt"); 
PLIO *out0 = new PLIO("DataOut1",adf::plio_32_bits, "data/output2.txt");
Figure 1. PL Table

Table 1. Column Description
Column Description
Name The port name of a PLIO connection and whether it is an input or output.
Data Width The data width of the PLIO connection defined in the constructor. The width can be either 32 bits, or 64 bits, or 128 bits.
Frequency (MHz) The frequency (in MHz) defined (optionally) in the PLIO constructor for the PLIO connection.
Buffers The number of buffers used in a PLIO connection. If a PLIO port is connected to a Window port of an AI Engine kernel two buffers are used, signifying a ping-pong buffer. A connection from a PLIO port to a stream port of the AI Engine kernel does not consume any buffers.
Connected Ports The number of ports the PLIO is connected to. This PLIO data can be multicasted to multiple destinations in the AI Engine. For more information see Multicast Support.
Column The interface column used by the PLIO, which is assigned by the aiecompiler. The values could be in the 0-49 range.
Channel The channel within the interface column used by the PLIO.
Packet ID The packet switching feature allows you to send packets of data to/from multiple destinations. These packets of data can be sent from/to the PL to/from the AI Engine. This column displays the ID of the packets used when packet switching is used. For more information see Explicit Packet Switching.