Renesas M32R-FPU - Manual (Page 130)

3
3-92 M32R-FPU Software Manual (Rev.1.01)
[Supplement]
This instruction is executed in two steps as shown below:
<step 1>
<step 2>
The value in the accumulator is altered depending on the supposed bit 80 through 7 after
left-shift operation and bit 8 through bit 63 after shift operation.
if bit 48 is 0 , there is no carry.
if bit 48 is 1 , the bit is carried.
Bits 48 to 63 are cleared to zero.
0000 7FFF FFFF 8000
positive
value
negative
value
0000 7FFF FFFF 7FFF
0000 0000 0000 0000
FFFF 8000 0000 8000
FFFF 8000 0000 7FFF
supposed sign
extended bit0-bit7 1-bit shift to the left
Value in Adest after the
execution of the RAC instruction
8 63 16 32 48
00 7FFF FFFF 0000
0 8 63
00
FF 8000 0000 0000
0 8 63
FF
47 48
8 63
0
48 8 63
0
••
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16 32 48 8 0
0
63
16 32 48 8 63 47
0
INSTRUCTIONS
3.2 Instruction description
RAC RAC DSP function instruction
Round accumulator