ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Instruction Details
A8.6.260 UXTAB
Unsigned Extend and Add Byte extracts an 8-bit value from a register, zero-extends it to 32 bits, adds the
result to the value in another register, and writes the final result to the destination register. You can specify
a rotation by 0, 8, 16, or 24 bits before extracting the 8-bit value.
Encoding T1 ARMv6T2, ARMv7
UXTAB ,,{,}
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 1 1 0 1 0 0 1 0 1 Rn 1 1 1 1 Rd 1 (0) rotate Rm
if Rn == ‘1111’ then SEE UXTB;
d = UInt(Rd); n = UInt(Rn); m = UInt(Rm); rotation = UInt(rotate:’000’);
if BadReg(d) || n == 13 || BadReg(m) then UNPREDICTABLE;
Encoding A1 ARMv6*, ARMv7
UXTAB ,,{,}
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
cond 0 1 1 0 1 1 1 0 Rn Rd rotate (0)(0) 0 1 1 1 Rm
if Rn == ‘1111’ then SEE UXTB;
d = UInt(Rd); n = UInt(Rn); m = UInt(Rm); rotation = UInt(rotate:’000’);
if d == 15 || m == 15 then UNPREDICTABLE;
A8-514 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B