Texas Instruments TMS320C67X/C67X+ DSP manual Instruction Type Execution Phases

Pipeline Execution of Instruction Types

Table 4−2. Execution Stage Length Description for Each Instruction Type (Continued)

		Instruction Type
Execution
phases	ADDDP/SUBDP	MPYI	MPYID	MPYDP
E1	Read lower sources	Read sources and	Read sources and	Read lower sources
	and start computation	start computation	start computation	and start computation
E2	Read upper sources	Read sources and	Read sources and	Read lower src1 and
	and continue	continue computation	continue computation	upper src2 and
	computation			continue computation
E3	Continue computation	Read sources and	Read sources and	Read lower src2 and
		continue computation	continue computation	upper src1 and
				continue computation
E4	Continue computation	Read sources and	Read sources and	Read upper sources
		continue computation	continue computation	and continue
				computation
E5	Continue computation	Continue computation	Continue computation	Continue computation
E6	Compute the lower	Continue computation	Continue computation	Continue computation
	results and write to
	register
E7	Compute the upper	Continue computation	Continue computation	Continue computation
	results and write to
	register
E8		Continue computation	Continue computation	Continue computation
E9		Complete computa-	Continue computation	Continue computation
		tion and write results	and write lower	and write lower
		to register	results to register	results to register

E10			Complete computa-
			tion and write upper
			results to register
Delay slots	6	8	9
Functional	2	4	4
unit latency

Complete computa- tion and write upper results to register

9

4

Notes: 1) This table assumes that the condition for each instruction is evaluated as true. If the condition is evaluated as false, the instruction does not write any results or have any pipeline operation after E1.

2) NOP is not shown and has no operation in any of the execution phases.

4-14 Pipeline SPRU733