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 88

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

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If n is 32 or more, then all the bits in the result are cleared to 0. 

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If n is 33 or more and the carry flag is updated, it is updated to 0.

Logical shift left by n bits moves the right-hand 32-n bits of the register Rm, to the left by n places, into the left-hand 32-n
bits of the result; and it sets the right-hand n bits of the result to 0. See 

The LSL #n operation can be used to multiply the value in the register Rm by 2

, if the value is regarded as an unsigned

integer or a two’s complement signed integer. Overflow can occur without warning.

When the instruction is LSLS or when LSL #n, with non-zero n, is used in Operand2 with the instructions MOVS, MVNS,
ANDS, ORRS, ORNS, EORS, BICS, TEQ or TST, the carry flag is updated to the last bit shifted out, bit[32-n], of the
register Rm. These instructions do not affect the carry flag when used with LSL #0.

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If n is 32 or more, then all the bits in the result are cleared to 0.

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If n is 33 or more and the carry flag is updated, it is updated to 0.

Rotate right by n bits moves the left-hand 32-n bits of the register Rm, to the right by n places, into the right-hand 32-n
bits of the result; and it moves the right-hand n bits of the register into the left-hand n bits of the result. See 

.

When the instruction is RORS or when ROR #n is used in Operand2 with the instructions MOVS, MVNS, ANDS, ORRS,
ORNS, EORS, BICS, TEQ or TST, the carry flag is updated to the last bit rotation, bit[n-1], of the register Rm.

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If n is 32, then the value of the result is same as the value in Rm, and if the carry flag is updated, it is updated to 
bit[31] of Rm. 

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ROR with shift length, n, more than 32 is the same as ROR with shift length n-32.