Encoding:

POOL32F

010101

rt

fs

00

MFC1

10000000

POOL32FXf

111011

6

5

5

2

8

6

Format: 

MFC1 rt, fs

microMIPS

Move Word From Floating Point

Purpose:

Move Word From Floating Point

To copy a word from an FPU (CP1) general register to a GPR.

Description: 

 GPR[rt] = FPR[fs]

The contents of FPR fs are sign-extended and loaded into general register rt.

Restrictions:

Operation: 

data = ValueFPR(fs, UNINTERPRETED_WORD)31..0
GPR[rt] = sign_extend(data)

Exceptions:

Coprocessor Unusable, Reserved Instruction

Historical Information:

For MIPS I, MIPS II, and MIPS III the contents of GPR rt are UNPREDICTABLE for the instruction immediately following MFC1.