Status Register (SREG) and Boolean Formula

I T H S V N Z C
– – – ⇔ 0 ⇔ ⇔ 1
S
N ⊕ V, for signed tests.
V

0

Cleared.

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 $00; cleared otherwise.

C

1

Set.

R (Result) equals Rd after the operation.

Example:

 com r4 ; Take one’s complement of r4
 breq zero ; Branch if zero
 ...
zero: nop ; Branch destination (do nothing)
Words
1 (2 bytes)
Cycles
1
Parent topic: COM – One’s Complement