Bit 4 (U):
This bit can be read and written by user software using the LCD, STC, ANDC,
ORC, and XORC instructions.
Bit 3 (N):
This bit indicates the most significant bit (the sign bit) of the result of an
Bit 2 (Z):
This bit is set to 1 to indicate a zero result and cleared to 0 to indicate a non-zero
Bit 1 (V):
This bit is set to 1 when an arithmetic overflow occurs and cleared to 0 when no
overflow occurs during an arithmetic operation.
Bit 0 (C):
This bit is set to 1 when a carry occurs and cleared to 0 when no carry occurs.
A carry can occur due to a carry from an add instruction, a borrow from a subtract
instruction, or a shift or rotate instruction.
The carry flag also has a bit accumulator function that is used by bit operation and
bit transfer instructions.