Fujitsu Fujitsu SPARC64 V manual Sync Synonym machine sync

in parallel. When instructions are committed, results in renamed registers are posted to the architected registers in the proper sequence to produce the correct program results.

scan A method used to initialize all of the machine state within a chip. In a chip that has been designed to be scannable, all of the machine state is connected in one or several loops called “scan rings.” Initialization data can be scanned into the chip through the scan rings. The state of the machine also can be scanned out through the scan rings.

reservation station A holding location that buffers dispatched instructions until all input operands are available. SPARC64 V implements dataflow execution based on operand availability. When operands are available, the instructions in the reservation station are scheduled for execution. Reservation stations also contain special tag-matching logic that captures the appropriate operand data. Reservation stations are sometimes referred to as queues (for example, the integer queue).

speculative A distribution system whereby a result is not guaranteed as known to be correct or an operand state is not known to be valid. SPARC64 V employs speculative distribution, meaning results can be distributed from functional units before the point at which guaranteed validity of the result is known.

superscalar An implementation that allows several instructions to be issued, executed, and committed in one clock cycle. SPARC64 V issues up to 4 instructions per clock cycle.

sync Synonym: machine sync.

syncing instruction An instruction that causes a machine sync. Thus, before a syncing instruction is issued, all previous instructions (in program order) must have been committed. At that point, the syncing instruction is issued, executed, completed, and committed by itself.

TLB Translation lookaside buffer.

Release 1.0, 1 July 2002 F. Chapter 2 Definitions 11