Renesas SuperH SH-4A - EXTU (Extend as Unsigned): Arithmetic Instruction

Rev. 1.50, 10/04, page 242 of 448
10.1.22 EXTU (Extend as Unsigned): Arithmetic Instruction
Format Operation Instruction Code Cycle T Bit
EXTU.B Rm,Rn Rm zero-extended from
byte → Rn
0110nnnnmmmm1100 1 —
EXTU.W Rm,Rn Rm zero-extended from
word → Rn
0110nnnnmmmm1101 1 —
Description: This instruction zero-extends the contents of general register Rm and stores the
result in Rn.
For a byte specification, 0 is transferred to Rn bits 8 to 31. For a word specification, 0 is
transferred to Rn bits 16 to 31.
Notes: None
Operation:
EXTUB(long m, long n) /* EXTU.B Rm,Rn */
{
R[n] = R[m];
R[n] &= 0x000000FF;
PC += 2;
}
EXTUW(long m, long n) /* EXTU.W Rm,Rn */
{
R[n] = R[m];
R[n] &= 0x0000FFFF;
PC += 2;
}
Example:
EXTU.B R0,R1 ;Before execution R0 = H'FFFFFF80
;After execution R1 = H'00000080
EXTU.W R0,R1 ;Before execution R0 = H'FFFF8000
;After execution R1 = H'00008000