Texas Instruments TMS320C67X/C67X+ DSP manual Saturate a 40-Bit Integer to a 32-Bit Integer

SAT Saturate a 40-Bit Integer to a 32-Bit Integer

				Saturate a 40-Bit Integer to a 32-Bit Integer
SAT
Syntax					SAT (.unit) src2, dst
					.unit = .L1 or .L2
Compatibility					C62x, C64x, C67x, and C67x+ CPU
Opcode
31	29	28	27	23		22	18	17	13	12	11	5	4	3	2	1	0

creg

z

dst

src2

0 0 0 0 0 x 1 0 0 0 0 0 0 1 1 0 s p

3	1	5	5	1	1	1
			Opcode map field used...	For operand type...	Unit
			src2	slong	.L1, .L2
			dst	sint

Description

Execution

Pipeline

A 40-bit src2 value is converted to a 32-bit value. If the value in src2 is greater than what can be represented in 32-bits, src2 is saturated. The result is placed in dst. If a saturate occurs, the SAT bit in the control status register (CSR) is set one cycle after dst is written.

if (cond)	{
	if (src2 > (231 − 1) )
	(231 − 1) → dst
	else if (src2 < −231)
	−231 → dst
	else src231..0 → dst
	}

else nop

Pipeline	E1
Stage
Read	src2
Written	dst
Unit in use	.L

Instruction Type	Single-cycle
Delay Slots	0

3-208 Instruction Set SPRU733