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

Instruction Details
A8.6.236 UBFX
Unsigned Bit Field Extract extracts any number of adjacent bits at any position from a register, zero-extends
them to 32 bits, and writes the result to the destination register.
Encoding T1 ARMv6T2, ARMv7
UBFX ,,#,#
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 0 (0) 1 1 1 1 0 0 Rn 0 imm3 Rd imm2 (0) widthm1
d = UInt(Rd); n = UInt(Rn);
lsbit = UInt(imm3:imm2); widthminus1 = UInt(widthm1);
if BadReg(d) || BadReg(n) then UNPREDICTABLE;
Encoding A1 ARMv6T2, ARMv7
UBFX ,,#,#
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 1 1 1 1 widthm1 Rd 1sb 1 0 1 Rn
d = UInt(Rd); n = UInt(Rn);
lsbit = UInt(lsb); widthminus1 = UInt(widthm1);
if d == 15 || n == 15 then UNPREDICTABLE;
A8-466 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B