6. Status Register (SREG)

The Status Register contains flags that indicate the results of arithmetic/logic operations. This register is crucial for branch instructions. 
 
 
 
 Bit 
 Name 
 Description 
 
 
 
 
 7 
 I (Global Interrupt Enable) 
 Enables/disables global interrupts 
 
 
 6 
 T (Bit Copy Storage) 
 Storage for BLD/BST instructions 
 
 
 5 
 H (Half Carry Flag) 
 Carry from bit 3 to bit 4 (for BCD) 
 
 
 4 
 S (Sign Flag) 
 S = N ⊕ V (for signed operations) 
 
 
 3 
 V (Overflow Flag) 
 Two's complement overflow 
 
 
 2 
 N (Negative Flag) 
 Result is negative (bit 7 = 1) 
 
 
 1 
 Z (Zero Flag) 
 Result = 0 
 
 
 0 
 C (Carry Flag) 
 Carry/borrow from operation