Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet

169

SAM4E [DATASHEET]

Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14

Bit Field Clear and Bit Field Insert.

Syntax

BFC{cond} Rd, #lsb, #width

BFI{cond} Rd, Rn, #lsb, #width

where:

cond

is an optional condition code, see 

.

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.

Operation

BFC clears a bitfield in a register. It clears width bits in Rd, starting at the low bit position lsb. Other bits in Rd are
unchanged.

BFI copies a bitfield into one register from another register. It replaces width bits in Rd starting at the low bit
position lsb, with width bits from Rn starting at bit[0]. Other bits in Rd are unchanged.

Restrictions

Do not use SP and do not use PC.

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.