Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Scheda Tecnica

 138

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

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Adds the signed accumulate value to the result of the subtraction.

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Writes the result of the addition to the destination register.

The SMLSLD instruction interprets the values from Rn and Rm as four signed halfwords. 
This instruction:

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Optionally rotates the halfwords of the second operand.

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Performs two signed 16 × 16-bit halfword multiplications.

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Subtracts the result of the upper halfword multiplication from the result of the lower halfword multiplication.

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Adds the 64-bit value in RdHi and RdLo to the result of the subtraction.

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Writes the 64-bit result of the addition to the RdHi and RdLo.

Restrictions

In these instructions:



Do not use SP and do not use PC.

Condition Flags

This instruction sets the Q flag if the accumulate operation overflows. Overflow cannot occur during the multiplications or
subtraction.

For the Thumb instruction set, these instructions do not affect the condition code flags.

Examples

SMLSD   R0, R4, R5, R6 ; Multiplies bottom halfword of R4 with bottom

                       ; halfword of R5, multiplies top halfword of R4

                       ; with top halfword of R5, subtracts second from

                       ; first, adds R6, writes to R0

SMLSDX  R1, R3, R2, R0 ; Multiplies bottom halfword of R3 with top

                       ; halfword of R2, multiplies top halfword of R3

                       ; with bottom halfword of R2, subtracts second from

                       ; first, adds R0, writes to R1

SMLSLD  R3, R6, R2, R7 ; Multiplies bottom halfword of R6 with bottom

                       ; halfword of R2, multiplies top halfword of R6

                       ; with top halfword of R2, subtracts second from

                       ; first, adds R6:R3, writes to R6:R3

SMLSLDX R3, R6, R2, R7 ; Multiplies bottom halfword of R6 with top

                       ; halfword of R2, multiplies top halfword of R6

                       ; with bottom halfword of R2, subtracts second from

                       ; first, adds R6:R3, writes to R6:R3.