Index
UXTB
Unsigned Extend Byte extracts an 8-bit value from a register, zero-extends it to the size of the register, and writes the result to the destination register.
This is an alias of UBFM. This means:
- The encodings in this description are named to match the encodings of UBFM.
- The description of UBFM gives the operational pseudocode, any CONSTRAINED UNPREDICTABLE behavior, and any operational information for this instruction.
| 31 |
30 |
29 |
28 |
27 |
26 |
25 |
24 |
23 |
22 |
21 |
20 |
19 |
18 |
17 |
16 |
15 |
14 |
13 |
12 |
11 |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0 |
1 |
0 |
1 |
0 |
0 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
Rn |
Rd |
| sf |
opc |
|
N |
immr |
imms |
|
|
32-bit
UXTB <Wd>, <Wn>
is equivalent to
UBFM <Wd>, <Wn>, #0, #7
and is always the preferred disassembly.
Assembler Symbols
| <Wd> |
Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. |
| <Wn> |
Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field. |
Operation
The description of UBFM gives the operational pseudocode for this instruction.
Operational information
If PSTATE.DIT is 1:
- The execution time of this instruction is independent of:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.
- The response of this instruction to asynchronous exceptions does not vary based on:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.