jump trace buffer

(JTB) A feature of some pipelined processors (e.g. Amulet,

Pentium?) which stores the source and destination addresses

of the last few branch instuctions executed. When a branch

instruction is fetched, its source is looked for in the JTB.

If found, the next instuction fetch will be from the previous

destination of that branch. If it turns out that the branch

shouldn't have been taken this time, then the pipeline is

flushed. This means that in a tight loop it is not

necessary to flush the pipeline every time you jump back to

the start.

(1994-12-15)