Renesas M32R-FPU - Manual (Page 109)

3
3-71 M32R-FPU Software Manual (Rev.1.01)
MACWHI MACWHI
DSP function instruction
Multiply-accumulate
word and high-order halfword
[Mnemonic]
MACWHI Rsrc1,Rsrc2
[Function]
Multiply and add
accumulator += ( ( signed ) Rsrc1 * ( signed short ) ( Rsrc2 >> 16 ) );
[Description]
MACWHI multiplies the 32 bits of Rsrc1 and the high-order 16 bits of Rsrc2, then adds the
result to the low-order 56 bits in the accumulator.
The LSB of the multiplication result is aligned with the LSB of the accumulator, and the portion
corresponding to bits 8 through 15 of the accumulator is sign extended before addition. The
result of addition is stored in the accumulator. The 32 bits of Rsrc1 and the high-order 16 bits of
Rsrc2 are treated as signed values.
The condition bit (C) is unchanged.
[EIT occurrence]
None
[Encoding]
high-order 16 bits
Rsrc1 32 bits
Rsrc2 x
0 15 16 31
+
0 15 16 31 32 47 48 63 7 8
Result of the multiplication
Value in accumulator before the
execution of the MACWHI instruction
Value in accumulator after the
execution of the MACWHI instruction
Sign extension
Sign extension
src1 0011 MACWHI Rsrc1,Rsrc2 src2 0110
INSTRUCTIONS
3.2 Instruction description