Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Fiche De Données

SAM4E [DATASHEET]

Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14

92



If adding two positive values results in a negative value



If subtracting a positive value from a negative value generates a positive value



If subtracting a negative value from a positive value generates a negative value.

The Compare operations are identical to subtracting, for CMP, or adding, for CMN, except that the result is
discarded. See the instruction descriptions for more information.

Note:

Most instructions update the status flags only if the S suffix is specified. See the instruction descriptions for more 
information.

The instructions that can be conditional have an optional condition code, shown in syntax descriptions as {cond}.
Conditional execution requires a preceding IT instruction. An instruction with a condition code is only executed if
the condition code flags in the APSR meet the specified condition. 

 shows the condition codes to use. 

A conditional execution can be used with the IT instruction to reduce the number of branch instructions in code.

 also shows the relationship between condition code suffixes and the N, Z, C, and V flags.

The example below shows the use of a conditional instruction to find the absolute value of a number. R0 =
ABS(R1).

MOVS 

R0, R1 

; R0 = R1, setting flags

IT 

MI 

; IT instruction for the negative condition

RSBMI 

R0, R1, #0 

; If negative, R0 = -R1

EQ

Z = 1

Equal

NE

Z = 0

Not equal

CS or HS

C = 1

Higher or same, unsigned 

≥

CC or LO

C = 0

Lower, unsigned < 

MI

N = 1

Negative

PL

N = 0

Positive or zero

VS

V = 1

Overflow

VC

V = 0

No overflow

HI

C = 1 and Z = 0

Higher, unsigned > 

LS

C = 0 or Z = 1

Lower or same, unsigned 

≤

GE

N = V 

Greater than or equal, signed 

≥

LT

N 

!= V

Less than, signed <

GT

Z = 0 and N = V

Greater than, signed >

LE

Z = 1 and N 

!= V 

Less than or equal, signed 

≤

AL

Can have any value

Always. This is the default when no suffix is specified.