MC68HC05K1 FREESCALE [Freescale Semiconductor, Inc], MC68HC05K1 Datasheet - Page 41

• Manufacturer Part Number: MC68HC05K1
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

3.4 Arithmetic/Logic Unit (ALU)
MC68HC05K0 • MC68HC05K1 — Rev. 2.0
N — Negative Flag
Z — Zero Flag
C — Carry/Borrow Flag
The ALU performs the arithmetic and logical operations defined by the
instruction set. The binary arithmetic circuits decode instructions and set
up the ALU for the selected operation.
The CPU sets the negative flag when an arithmetic operation, logical
operation, or data manipulation produces a negative result. Reset has
no effect on the negative flag.
The CPU sets the zero flag when an arithmetic operation, logical
operation, or data manipulation produces a result of $00. Reset has
no effect on the zero flag.
The CPU sets the carry/borrow flag when an addition operation
produces a carry out of bit 7 of the accumulator or when a subtraction
operation requires a borrow. Some logical operations and data
manipulation instructions also clear or set the carry/borrow flag. Reset
has no effect on the carry/borrow flag.
Freescale Semiconductor, Inc.
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Central Processor Unit (CPU)
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Central Processor Unit (CPU)
Arithmetic/Logic Unit (ALU)
Technical Data