2.6.8.1.1 Syntax
BFC{cond} Rd, #lsb, #width
BFI{cond} Rd, Rn, #lsb, #width
where:
cond is an optional condition code, see 2.6.3.7 Conditional Execution.
Rd is the destination register.
Rn is the source register.
lsb is the position of the least significant bit of the bitfield. lsb must be in the range 0 to 31.
width is the width of the bitfield and must be in the range 1 to 32-lsb.