Motorola MCF5281 用户手册
2-30
MCF5282 User’s Manual
MOTOROLA
ColdFire Instruction Set Architecture Enhancements
BYTEREV
Byte Reverse Register
BYTEREV
(Supported Starting with ISA A+)
Operation:
Byte Reversed Dx
→ Dx
Assembler Syntax:
BYTEREV.L Dx
Attributes:
Size = longword
The contents of the destination data register are byte-reversed as defined below:
Condition Codes:
Not affected
Instruction Field:
•
Register field—Specifies the destination data register, Dx.
Instruction
Format:
Format:
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
1
0
1
1
0
0
0
Register, Dx
new Dx[31:24]
= old Dx[7:0]
new Dx[23:16]
= old Dx[15:8]
new Dx[15:8]
= old Dx[23:16]
new Dx[7:0]
= old Dx[31:24]
BYTEREV
V2, V3 Core (ISA_A)
V4 Core (ISA_B)
V2 Core (ISA_A+)
Opcode present
No
No
Yes