Freescale Semiconductor SC140 Extract Extract Signed Bit Field Dalu, Extract #$c,#$e,d2,d4

		EXTRACT
EXTRACT Extract Signed Bit Field (DALU)		EXTRACT
Operation	Assembler Syntax
Db[(offset + width – 1):offset] → Dn[(width – 1):0]
Db[offset + width – 1] → Dn[39:width] (sign-extension)
width = #U6; offset = #u6	EXTRACT #U6,#u6,Db,Dn
	{0 ≤ U6 ≤ 40}{0 ≤ u6 ≤ 40}
	{#U6+#u6 ≤	40}
width = Da[13:8]; offset = Da[5:0]	EXTRACT Da,Db,Dn
	{0 ≤ Da[13:8] ≤ 40}

{0 ≤ Da[5:0] ≤ 40} {Da[13:8]+Da[5:0] ≤ 40}

Description

These operations extract a bit field from a source data register (Db) and place it in a destination data register (Dn), right-aligned and sign-extended from the MSB of the extracted bit field. The extracted field is a signed integer. If the offset is zero, this instruction can be used to sign-extend an arbitrary width signed integer.

EXTRACT #U6,#u6,Db,Dn

Uses two immediate unsigned 6-bit integers for the width (#U6) and offset (#u6).

EXTRACT Da,Db,Dn

Uses a supplemental data register (Da) for the width (bits 13–8) and the offset (bits 5–0).

Status and Conditions that Affect Instruction

None.

Status and Conditions Changed by Instruction

Register Address	Bit Name	Description
Ln	L	Clears the Ln bit in the destination register.

Example

extract #$c,#$e,d2,d4

Register/Memory Address

immediate (width)

immediate (offset)

D2

L4:D4

Before

$C

$E

$FF 8665 4321

$0:$00 0000 0000

After

$0:$FF FFFF F995

SC140 DSP Core Reference Manual A-171