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The PIC instruction set refers to the set of instructions that a Microchip Technology PIC or dsPIC microcontroller supports. The instructions are usually programmed into the Flash memory of the processor, and automatically executed by the microcontroller on startup. PICmicro chips have a Harvard architecture, and instruction words are unusual sizes. Originally, 12-bit instructions included 5 address bits to specify the memory operand, and 9-bit branch destinations. Later revisions added opcode bits, allowing additional address bits. ==Baseline core devices (12 bit)== The instruction set is as follows. Register numbers are referred to as "f", while constants are referred to as "k". Bit numbers (0–7) are selected by "b". The "d" bit selects the destination: 0 indicates W, while 1 indicates that the result is written back to source register f. The C and Z status flags may be set based on the result; otherwise they are unmodified. Add and subtract (but not rotate) instructions that set C also set the DC (digit carry) flag, the carry from bit 3 to bit 4, which is useful for BCD arithmetic. Models with more than 32 bytes of registers (special function registers plus RAM) support multiple banks of registers. There are two methods of doing this: # Most use high high-order bits of the file select register to select the current register bank. # Some more recent models have a separate 3-bit bank select register, and a MOVLB instruction to set it. *: Extended instruction, not available on most 12-bit PICs. Of the models with extended RAM, most (e.g. 16C5x, 16F5x) extend the register address space using the high-order bits of the FSR. A few (e.g. PIC12F529T39A) have a separate bank select register which can be set with this instruction. †: Extended instruction, only available on "enhanced baseline" PICs. Only the very few models (16F527, 16F570, MCV20A) with interrupt support (and a 4-level stack) include these instructions. All such models also include MOVLB. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「PIC instruction listings」の詳細全文を読む スポンサード リンク
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