Encoding:

POOL32A

000000

rt

rs

INSV

0100000100

POOL32Axf

111100

6

5

5

10

6

SPECIAL3

011111

rs

rt

0

00000

0

00000

INSV

001100

6

5

5

5

5

6

Format: 

INS rt, rs

microMIPSDSP

Insert Bit Field Variable

Restrictions:

The operation is UNPREDICTABLE if lsb > msb.

If either register rs or register rt does not contain sign-extended 32-bit values (bits 63..31 equal), then the result of the operation is UNPREDICTABLE.

Operation: 

if (lsb > msb) or (NotWordValue(GPR[rs])) or (NotWordValue(GPR[rt]))) then
   UNPREDICTABLE
endif
GPR[rt]63..0 = (GPR[rt]31)32 || GPR[rt]31..msb+1 || GPR[rs]msb-lsb..0 || GPR[rt]lsb-1..0

Exceptions:

Reserved Instruction, DSP Disabled