Returns the oldest element of a FIFO without removing the oldest element.
Peek FIFO is supported on all local, DMA host-to-target, and peer-to-peer reader FIFOs, regardless of the implementation type.
Reference to the FIFO.
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Default: No error
Boolean value that specifies whether downstream nodes are ready for this node to return a new value.
Use Feedback Node to wire this input to the ready for input input of a downstream node. If this input is False during a given cycle, output valid returns False during that cycle.
True | The downstream node is ready for the next data element. |
False | The downstream node is not ready for the next data element. |
Default: False
Reference to the FIFO.
Oldest data element in the FIFO.
If the FIFO is empty, data returns an undefined element.
Error information.
The node produces this output according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Boolean value that indicates whether this node computes a result that downstream nodes can use.
Wire this output to the input valid input of a downstream node to transfer data from the node to the downstream node.
True | Downstream nodes can use the result this node computes. |
False | This node returns an undefined value that downstream nodes cannot use. |
Because this node may return invalid data in certain cases, such as when the FIFO is being cleared or the FIFO is currently empty, this node uses the four-wire handshake protocol to alert you if this node returns invalid data. Check the status of output valid to ensure the data output is valid.