SAM4N_14 Datasheet, PDF (126/795 Pages) ATMEL Corporation – ARM-based Flash MCU

13.6.5.18UHADD16 and UHADD8
Unsigned Halving Add 16 and Unsigned Halving Add 8
Syntax
op{cond}{Rd,} Rn, Rm
where:
op
is any of:
UHADD16 Unsigned Halving Add 16.
UHADD8 Unsigned Halving Add 8.
cond
is an optional condition code, see “Conditional Execution” .
Rd
is the destination register.
Rn
is the register holding the first operand.
Rm
is the register holding the second operand.
Operation
Use these instructions to add 16- and 8-bit data and then to halve the result before writing the result to the destination
register:
The UHADD16 instruction:
1. Adds each halfword from the first operand to the corresponding halfword of the second operand.
2. Shuffles the halfword result by one bit to the right, halving the data.
3. Writes the unsigned results to the corresponding halfword in the destination register.
The UHADD8 instruction:
1. Adds each byte of the first operand to the corresponding byte of the second operand.
2. Shuffles the byte result by one bit to the right, halving the data.
3. Writes the unsigned results in the corresponding byte in the destination register.
Restrictions
Do not use SP and do not use PC.
Condition Flags
These instructions do not change the flags.
Examples
UHADD16 R7, R3
UHADD8 R4, R0, R5
; Adds halfwords in R7 to corresponding halfword of R3
; and writes halved result to corresponding halfword
; in R7
; Adds bytes of R0 to corresponding byte in R5 and
; writes halved result to corresponding byte in R4.
SAM4N Series [DATASHEET]
11158A–ATARM–07-Jun-13
126