port<T> - 2021.2 English

Versal ACAP AI Engine Programming Environment User Guide (UG1076)

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

Scope

Objects of type port<T> are port objects that can be declared in class scope as member variables of a user-defined graph type (i.e., member variables of a class that inherits from graph), or they are defined implicitly for a kernel according to its function signature. The template parameter T can be one of input, output, or inout.

Aliases

input_port is an alias for the type port<input>.

output_port is an alias for the type port<output>.

inout_port is an alias for the type port<inout>.

Purpose

Used to connect between kernels within a graph and across levels of hierarchy in customer specification containing platform, graphs, and subgraphs.

Operators

port<T>& negate(port<T>&)

When applied to a destination port within a connection, this operator inverts the Boolean semantics of the source port to which it is connected. Therefore, it has the effect of converting a 0 to 1 and 1 to 0.

port<T>& async(port<T>&)

When applied to a destination RTP port within a connection, this operator specifies an asynchronous update of the destination port's RTP buffer from the source port that it is connected to or from the external control application if the source is a graph port left unconnected. Therefore, the receiving kernel does not wait for the value for each invocation, rather it uses previous value stored in the corresponding buffer.

When applied to a source or destination window port, this operator specifies that the window object will not be synchronized upon kernel entry. Instead, the window_acquire and window_release APIs must be used to manage the window object synchronization explicitly within the kernel code.

port<T>& sync(port<T>&)

When applied to a source RTP port within a connection, this operator specifies a synchronous read of the source port's RTP buffer from the destination port that it is connected to or from the external control application if the destination is a graph port left unconnected. Therefore, the receiving kernel waits for a new value to be produced for each invocation of the producing kernel.