ST STM32H7 Series User Manual

The STM32 Cortex-M4 instruction set PM0214
140/262 PM0214 Rev 9
3.9.2 SBFX and UBFX
Signed Bit Field Extract and Unsigned Bit Field Extract.
Syntax
SBFX{cond} Rd, Rn, #lsb, #width
UBFX{cond} Rd, Rn, #lsb, #width
Where:
• ‘cond’ is an optional condition code, see Conditional execution on page 65.
• ‘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
SBFX extracts a bitfield from one register, sign extends it to 32 bits, and writes the result to
the destination register.
UBFX extracts a bitfield from one register, zero extends it to 32 bits, and writes the result to
the destination register.
Restrictions
Do not use SP and do not use PC.
Condition flags
These instructions do not affect the flags.
Examples
SBFX R0, R1, #20, #4 ; Extract bit 20 to bit 23 (4 bits) from R1 and sign
; extend to 32 bits and then write the result to R0.
UBFX R8, R11, #9, #10; Extract bit 9 to bit 18 (10 bits) from R11 and zero
; extend to 32 bits and then write the result to R8

ST STM32H7 Series Specifications

General

Brand	ST
Model	STM32H7 Series
Category	Computer Hardware
Language	English