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MC9S08GB60 Datasheet, PDF (126/290 Pages) Motorola, Inc – Microcontrollers | |||
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Central Processor Unit (CPU)
8.2 Features
Features of the HCS08 CPU include:
⢠Object code fully upward-compatible with M68HC05 and M68HC08 Families
⢠All registers and memory are mapped to a single 64-Kbyte address space
⢠16-bit stack pointer (any size stack anywhere in 64-Kbyte address space)
⢠16-bit index register (H:X) with powerful indexed addressing modes
⢠8-bit accumulator (A)
⢠Many instructions treat X as a second general-purpose 8-bit register
⢠Seven addressing modes:
â Inherent â Operands in internal registers
â Relative â 8-bit signed offset to branch destination
â Immediate â Operand in next object code byte(s)
â Direct â Operand in memory at $0000â$00FF
â Extended â Operand anywhere in 64-Kbyte address space
â Indexed relative to H:X â Five submodes including auto increment
â Indexed relative to SP â Improves C efï¬ciency dramatically
⢠Memory-to-memory data move instructions with four address mode combinations
⢠Overï¬ow, half-carry, negative, zero, and carry condition codes support conditional branching on
the results of signed, unsigned, and binary-coded decimal (BCD) operations
⢠Efï¬cient bit manipulation instructions
⢠Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions
⢠STOP and WAIT instructions to invoke low-power operating modes
8.3 Programmerâs Model and CPU Registers
Figure 8-1 shows the ï¬ve CPU registers. CPU registers are not part of the memory map.
MC9S08GB/GT Data Sheet, Rev. 2.3
126
Freescale Semiconductor
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