MC68HC705P9CDW FREESCALE [Freescale Semiconductor, Inc], MC68HC705P9CDW Datasheet - Page 49

• Manufacturer Part Number: MC68HC705P9CDW
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

4.7 Instruction Set
MC68HC705P9 — Rev. 4.0
MOTOROLA
I — Interrupt Mask
N — Negative Flag
Z — Zero Flag
C — Carry/Borrow Flag
The MCU instruction set has 62 instructions and uses eight addressing
modes. The instructions include all those of the M146805 CMOS Family
plus one more: the unsigned multiply (MUL) instruction. The MUL
instruction allows unsigned multiplication of the contents of the
accumulator (A) and the index register (X). The high-order product is
stored in the index register, and the low-order product is stored in the
accumulator.
Setting the interrupt mask disables interrupts. If an interrupt request
occurs while the interrupt mask is logic zero, the CPU saves the CPU
registers on the stack, sets the interrupt mask, and then fetches the
interrupt vector. If an interrupt request occurs while the interrupt mask
is set, the interrupt request is latched. Normally, the CPU processes
the latched interrupt as soon as the interrupt mask is cleared again.
A return from interrupt (RTI) instruction pulls the CPU registers from
the stack, restoring the interrupt mask to its cleared state. After any
reset, the interrupt mask is set and can be cleared only by a software
instruction.
The CPU sets the negative flag when an arithmetic operation, logical
operation, or data manipulation produces a negative result.
The CPU sets the zero flag when an arithmetic operation, logical
operation, or data manipulation produces a result of $00.
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.
Freescale Semiconductor, Inc.
For More Information On This Product,
Central Processor Unit (CPU)
Go to: www.freescale.com
Central Processor Unit (CPU)
Technical Data
Instruction Set
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