AVR Microcontrollers
AVR Instruction Set Manual
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Instruction Set Nomenclature
Status Register (SREG)
SREG Status Register
C Carry Flag
Z Zero Flag
N Negative Flag
V Two’s complement overflow indicator
S N ⊕ V, for signed tests
H Half Carry Flag
T Transfer bit used by BLD and BST instructions
I Global Interrupt Enable/Disable Flag
Registers and Operands
Rd: Destination (and source) register in the Register File
Rr: Source register in the Register File
R: Result after instruction is executed
K: Constant data
k: Constant address
b: Bit in the Register File or I/O Register (3-bit)
s: Bit in the Status Register (3-bit)
X,Y,Z: Indirect Address Register (X=R27:R26, Y=R29:R28, and
Z=R31:R30)
A: I/O location address
q: Displacement for direct addressing (6-bit)
Atmel-0856L-AVR-Instruction-Set-Manual_Other-11/2016