MC68HC16Z1CAG16 Datasheet, PDF (94/500 Pages) Freescale Semiconductor, Inc – M68HC16Z Series users manual

Freescale Semiconductor, Inc.
8-Bit Opcode with 8-Bit Operand
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8-Bit Opcode with 4-Bit Index Extensions
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8-Bit Opcode, Argument(s)
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8-Bit Opcode with 8-Bit Prebyte, No Argument
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8-Bit Opcode with 8-Bit Prebyte, Argument(s)
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8-Bit Opcode with 20-Bit Argument
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Figure 4-4 Basic Instruction Formats
4.10 Execution Model
This description builds up a conceptual model of the mechanism the CPU16 uses to
fetch and execute instructions. The functional divisions in the model do not necessarily
correspond to physical subunits of the microprocessor.
As shown in Figure 4-5, there are three functional blocks involved in fetching, decod-
ing, and executing instructions. These are the microsequencer, the instruction pipe-
line, and the execution unit. These elements function concurrently. All three may be
active at any given time.
4-34
CENTRAL PROCESSING UNIT
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M68HC16 Z SERIES
USER’S MANUAL