Encoding:

Format:

MTC1 rt, fs

Purpose:

Move Word to Floating Point

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

Description:

 FPR[fs] = GPR[rt]

The low word in GPR rt is placed into the low word of FPR fs. If FPRs are 64 bits wide, bits 63..32 of FPR fs become

UNPREDICTABLE.

Restrictions:

Operation:

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

Exceptions:

Coprocessor Unusable

Historical Information:

For MIPS I, MIPS II, and MIPS III the value of FPR fs is UNPREDICTABLE for the instruction immediately following MTC1.