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Home  BasePack DStruct Class TFifo How to use FIFOs |
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| See also: GetByte, PutByte, Create, Class TFifo |   |
Using TFifo |
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FIFO (First In, First Out) registers are mainly used in programs where some asynchronous data stream has to be managed. A FIFO can be seen as circular buffers of a given fixed length. Any FIFO has a method to input data at one end and to read data from it at the other end. The figure below shows a typical implementation of a FIFO buffer.
In order to use it, first an instance of the class TFifo has to be created - either by drag and drop from the component palette, or by creating an instance at runtime:
const SizeOfFifo = 1000; ... AnyFifo := TFifo.Create (Form1); AnyFifo.Size := SizeOfFifo; ... Thereafter data can be written to the FIFO by using the method PutByte:
repeat until PutByte (cc) = True; The loop ensures that the byte in parameter cc is delivered in any case. Note, that such a loop could also have some advert effect by blocking the system when the FIFO is not emptied by some other process. In order to retrieve data from a FIFO, you should use the method GetData:
if GetByte (cc) then
begin
{... here goes some user code}
end;
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Last Update: 2023-Feb-06