Operator EventDataToHost

Operator Library: Base

The operator generates software events with data payload. The payload size can be configured as N 16-bit data words via the PayloadSize parameter.

The operator has a 16-bit data input I and a 1-bit strobe input S. The inputs are O-synchronous. The input S starts a new event. Any data which arrives at I before S is asserted is ignored. S may be asserted for more than one data cycle but once S is de-asserted it may not be asserted again before the payload data for the ongoing event is completed. If an automatic clearance is set (see parameter AutoClear), then S can even be constantly 1.

The parameter AutoClear defines at which time clearance is done so that another event can be triggered:

  • EoL: Another event may be started after the next end of line. As soon as the N-th data is ready, no further event data is accepted until the end of the line, independent of the state of S. Starting with the next line, a new event may be generated with S=1.

  • EoF: Another event may be started after the next end of frame. As soon as the N-th data is ready, no further event data is accepted until the end of the frame, independent of the state of S. Starting with the next frame, a new event may be generated with S=1.

  • NONE: No auto-clearance. S must transfer a 0 for at least one data cycle after the event strobe to activate that event data for a subsequent event is accepted. Note that once S is de-asserted, it may not be asserted again before the payload data for the ongoing event is completed.

The operator stores the data payload and triggers the event as soon as N words of data have been received from I. If the event data is incomplete at the time when auto clearance happens, no event is generated and the incomplete payload data is deleted.

The input of the operator is never blocked. As the capacity of the event transfer buffers is limited, overflow may occur when the event rate is too high. To detect data loss, it may be useful to include a sequential number in your event data.

The triggered event is identified by the software application by using the unique event name via EventName parameter (see parameter description below).

The operator uses one resource of type EventPort exclusively. You can modify the resource EventPort. EventPort specifies which event channel is used by the software. Each EventPort number can only be used once in a design.

In addition, one resource of type EventID is reserved. You can't modify this resource (therefore it is greyed out), because the EventID is generated automatically. If you copy & paste an operator instance, and thus have the same EventID in different operator instances, you must delete one of these instances and instantiate the operator anew.

[Tip] Limited Amount of Event Ports and of Individual Events

The maximum amount of event ports available in a design depends on the target hardware platform you are designing for (see ' Device Resources of Supported Platforms ' for detailed information).

If you design an applet for use in the runtime environment, you can use a maximum of 64 individual events in a design.

I/O Properties

Property Value
Operator Type M
Input Links I, Input for payload data.
S, Strobe for starting new event.

Supported Link Format

Link Parameter Input Link I Input Link S
Bit Width 16 1
Arithmetic unsigned unsigned
Parallelism 1 1
Kernel Columns 1 1
Kernel Rows 1 1
Img Protocol {VALT_IMAGE2D, VALT_LINE1D, VALT_PIXEL0D} {VALT_IMAGE2D, VALT_LINE1D, VALT_PIXEL0D}
Color Format VAF_GRAY VAF_GRAY
Color Flavor FL_NONE FL_NONE
Max. Img Width any any
Max. Img Height any any

Parameters

EventsWithTimestamp
Type static/dymanic write parameter
Default ON
Range {ON,OFF}

Defines whether high-precision timestamps are attached to each event.
ON: Timestamps are generated.
OFF: No timestamps are generated.

EventName
Type static write parameter
Default Event
Range

This event name is used to identify and use a particular event signal in the Framegrabber SDK.

PayloadSize
Type static parameter
Default 1
Range [1, 254]

Set the payload size as a number of 16-bit data words.

AutoClear
Type static parameter
Default NONE
Range {NONE, EoL, EoF}

Defines at which time clearance is done so another event can be triggered.

When EoL is set, then after the next end of line another event may be started. As soon as the N-th data is ready, no further event data is accepted until the end of the line, independent of the state of S. Starting with the next line, a new event may be generated with S=1.

When EoF is set, then after the next end of frame another event may be started. As soon as the N-th data is ready, no further event data is accepted until the end of the frame, independent of the state of S. Starting with the next frame, a new event may be generated with S=1.

When NONE is set, then S must transfer a 0 for at least one data cycle after the event strobe to activate that event data for a subsequent event is accepted. Note that once S is de-asserted, it may not be asserted again before the payload data for the ongoing event is completed.

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