Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

 110

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

Count Leading Zeros.

Syntax

CLZ{cond} Rd, Rm

where:

cond

Rd

is the destination register.

Rm

is the operand register.

Operation

The CLZ instruction counts the number of leading zeros in the value in Rm and returns the result in Rd. The result value
is 32 if no bits are set and zero if bit[31] is set.

Restrictions

Do not use SP and do not use PC.

Condition Flags

This instruction does not change the flags.

Examples

    CLZ      R4,R9

    CLZNE    R2,R3

Compare and Compare Negative.

Syntax

CMP{cond} Rn, Operand2

CMN{cond} Rn, Operand2

where:

cond

Rn

is the register holding the first operand.

Operand2

is a flexible second operand. See 

options

Operation

These instructions compare the value in a register with Operand2. They update the condition flags on the result, but do
not write the result to a register.

The CMP instruction subtracts the value of Operand2 from the value in Rn. This is the same as a SUBS instruction,
except that the result is discarded.

The CMN instruction adds the value of Operand2 to the value in Rn. This is the same as an ADDS instruction, except that
the result is discarded.

Restrictions

In these instructions:



Do not use PC



Operand2 must not be SP.

Condition Flags

These instructions update the N, Z, C and V flags according to the result.

Examples