MC68HC705P9CDW FREESCALE [Freescale Semiconductor, Inc], MC68HC705P9CDW Datasheet - Page 46

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

Central Processor Unit (CPU)
4.6 CPU Registers
4.6.1 Accumulator
4.6.2 Index Register
Technical Data
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Reset:
Reset:
Read:
Read:
Write:
Write:
The M68HC05 CPU contains five registers that control and monitor MCU
operation:
CPU registers are not memory mapped.
The accumulator is a general-purpose 8-bit register. The CPU uses the
accumulator to hold operands and the results of arithmetic and logic
operations.
The index register can be used for data storage or as a counter. In the
indexed addressing modes, the CPU uses the byte in the index register
to determine the effective address of the operand.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Accumulator
Index register
Stack pointer
Program counter
Condition code register
Bit 7
Bit 7
Central Processor Unit (CPU)
Go to: www.freescale.com
6
6
Figure 4-3. Index Register (X)
Figure 4-2. Accumulator (A)
5
5
Unaffected by reset
Unaffected by reset
4
4
3
3
MC68HC705P9 — Rev. 4.0
2
2
1
1
MOTOROLA
Bit 0
Bit 0