Atmel SAM4S Series, Preliminary Data Sheet

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158
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
• Subtracts the respective bytes of the second operand from the respective bytes of the first
operand.
• Saturates the results of the differences for each byte in the destination register to the
unsigned range 0 £ x £ 2
8
-1, where x is 8.
Restrictions
Do not use SP and do not use PC
.
Condition Flags
These instructions do not affect the condition code flags.
Examples
UQADD16 R7, R4, R2 ; Adds halfwords in R4 to corresponding halfword in R2,
; saturates to 16 bits, writes to corresponding
; halfword of R7
UQADD8 R4, R2, R5 ; Adds bytes of R2 to corresponding byte of R5,
; saturates to 8 bits, writes to corresponding bytes of
; R4
UQSUB16 R6, R3, R0 ; Subtracts halfwords in R0 from corresponding halfword
; in R3, saturates to 16 bits, writes to corresponding
; halfword in R6
UQSUB8 R1, R5, R6 ; Subtracts bytes in R6 from corresponding byte of R5,
; saturates to 8 bits, writes to corresponding byte of
; R1.
11.6.8 Packing and Unpacking Instructions
The table below shows the instructions that operate on packing and unpacking data:
Table 11-23. Packing and Unpacking Instructions
Mnemonic Description
PKH Pack Halfword
SXTAB Extend 8 bits to 32 and add
SXTAB16 Dual extend 8 bits to 16 and add
SXTAH Extend 16 bits to 32 and add
SXTB Sign extend a byte
SXTB16 Dual extend 8 bits to 16 and add
SXTH Sign extend a halfword
UXTAB Extend 8 bits to 32 and add
UXTAB16 Dual extend 8 bits to 16 and add
UXTAH Extend 16 bits to 32 and add
UXTB Zero extend a byte
UXTB16 Dual zero extend 8 bits to 16 and add
UXTH Zero extend a halfword