6.61.2 Status Register and Boolean Formula

S

N ⊕ V, for signed tests.

V

R7 ∧ R6 ∧ R5 ∧ R4 ∧ R3 ∧ R2 ∧ R1 ∧ R0

Set if two’s complement overflow resulted from the operation; cleared otherwise. Two’s complement overflow occurs only if Rd was 0x7F before the operation.

N

R7

Set if MSB of the result is set; cleared otherwise.

Z

R7 ∧ R6 ∧ R5 ∧ R4 ∧ R3 ∧ R2 ∧ R1 ∧ R0

Set if the result is 0x00; cleared otherwise.

R (Result) equals Rd after the operation.

Example:

      clr   r22       ; clear r22
loop: 
      inc   r22       ; increment r22
      ...
      cpi   r22,0x4F  ; Compare r22 to 0x4f
      brne  loop      ; Branch if not equal
      nop             ; Continue (do nothing)

Words

1 (2 bytes)