Trace data transfer system having burst and minimum threshold inputs
This invention controls data transmission from a data source to a sink. The data source buffers the data. The data source signaling to transmit data upon storing a burst amount of data. The data source may include a plurality of data sources. A merge unit merges data by receiving and retransmitting data from each data source which signals to transmit and inserting a source identity block each time the merged data is received from a different source.
1. A trace data transfer system comprising:
A. request logic having a valid output lead, a ready input lead, and a threshold control input lead;
B. first multiplexer circuitry having a control input, a burst threshold input, a minimum threshold input, and a threshold control output coupled to the threshold control input lead; and
C. flip-flop circuitry having a non-inverting output coupled to the control input of the first multiplexer circuitry.
2. The system of claim 1 in which the flip-flop circuitry has a data input and a clock input, and including second multiplexer circuitry having a control input coupled with the non-inverting output of the flip-flop circuitry, a flush input, and a second input, and gating circuitry having a no data input, a burst enable input, and an output coupled to the second input of the second multiplexer circuitry.
3. The system of claim 1 in which the request logic produces a ready signal only if an amount of data to be transmitted equals or exceeds a burst threshold indicated by the burst threshold input.
4. The system of claim 1 in which the request logic produces a ready signal only if an amount of data to be transmitted equals or exceeds a minimum threshold indicated by the minimum threshold input.