Forward Trace Using Circular Memory
Original Publication Date: 1981-Nov-01
Included in the Prior Art Database: 2005-Feb-12
A forward trace mechanism utilizes a circular, or wrap-around, memory for storing data for N machine cycles. In response to a start (or "sync") pulse, storage begins at an arbitrary location in the trace memory, and a cycle counter is reset. After N cycles, with the counter being incremented each cycle, tracing ceases. The primary advantage of this system is that the system will record trace data for N cycles following a start pulse even if the new start pulse occurs while a trace is already taking place. In such a case, tracing will simply continue, without interruption, with a reset cycle counter. If no new start pulse occurs, tracing will cease after N cycles.