Motorola M6800 - Manual (Page 6)

MPU-6
Stack Pointer Address-5 : Contents of ACCB
Stack Pointer Address-6 : Contents of CC
After the status of each register is stored on the stack, the Stack
Pointer will be decremented. When the stack is unloaded (status of registers
restored), the status of the last register on the stack will be the first
register that is restored.
Condition Code Register (CC)
The condition code register is an 8 bit register. Each individual
bit may get set or get cleared from execution of an instruction. To see how
each instruction effects the condition code register, refer to the M6800
programming manual. The primary use of this register is execution of the
conditional branch instruction. Bit 6 and 7 are not used and remain at logic
"1."
BIT N0. FUNCTION
0 C (Carry-Borrow Test)
1 V (Overflow Test)
2 Z (Zero Test)
3 N (Negative Test)
4 I (Interrupt Mask Test)
5 H (Half Carry Test)