2.6.8.1.4 Condition Flags
These instructions do not affect the flags.
Examples
BFC R4, #8, #12 ; Clear bit 8 to bit 19 (12 bits) of R4 to 0
BFI R9, R2, #8, #12 ; Replace bit 8 to bit 19 (12 bits) of R9 with
; bit 0 to bit 11 from R2.