Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO Data Sheet
Product codes
ATSAM4S-XPRO
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
142
12.6.5.24USUB16 and USUB8
Unsigned Subtract 16 and Unsigned Subtract 8
Syntax
Syntax
op{cond}{Rd,} Rn, Rm
where
opis any of:
USUB16 Unsigned Subtract 16.
USUB8 Unsigned Subtract 8.
condis an optional condition code, see
opis any of:
USUB16 Unsigned Subtract 16.
USUB8 Unsigned Subtract 8.
condis an optional condition code, see
.
Rdis the destination register.
Rnis the first operand register.
Rmis the second operand register.
Operation
Use these instructions to subtract 16-bit and 8-bit data before writing the result to the destination register:
The USUB16 instruction:
Rnis the first operand register.
Rmis the second operand register.
Operation
Use these instructions to subtract 16-bit and 8-bit data before writing the result to the destination register:
The USUB16 instruction:
1. Subtracts each halfword from the second operand register from the corresponding halfword of the first operand
register.
2. Writes the unsigned result in the corresponding halfwords of the destination register.
The USUB8 instruction:
1. Subtracts each byte of the second operand register from the corresponding byte of the first operand register.
2. Writes the unsigned byte result in the corresponding byte of the destination register.
Restrictions
Do not use SP and do not use PC
Do not use SP and do not use PC
.
Condition Flags
These instructions do not change the flags.
Examples
These instructions do not change the flags.
Examples
USUB16 R1, R0 ; Subtracts halfwords in R0 from corresponding halfword of R1
; and writes to corresponding halfword in R1USUB8
R4, R0, R5
; Subtracts bytes of R5 from corresponding byte in R0 and
; writes to the corresponding byte in R4.