PD17012_15 Datasheet, PDF (57/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
7.2 Configuration and Function of Each Block
7.2.1 ALU
The ALU executes arithmetic or logical operations, bit judgment, comparison, rotation processing, and
transfer of 4-bit data according to an instruction specified by the program.
7.2.2 Temporary registers A and B
Temporary registers A and B temporarily store 4-bit data.
These registers are automatically used when an instruction is executed and are not controlled by the program.
7.2.3 Program status word
The program status word controls the operation of the ALU and stores the status of the ALU.
For details of the program status word, refer to 5.8 Program Status Word (PSWORD).
7.2.4 Decimal adjuster
If the BCD flag of the program status word is set to 1 as a result of an executed arithmetic operation, the
arithmetic operation result is converted into a decimal number by the decimal adjuster.
7.2.5 Address controller
The address controller specifies an address of the data memory.
At this time, address modification by the index register and data memory row address pointer is also
controlled.
7.3 ALU Processing Instruction List
Table 7-1 lists the ALU operations when each instruction is executed.
Table 7-2 shows modification of data memory addresses by the index register and data memory row address
pointer.
Table 7-3 shows the decimal adjustment data when a decimal operation is executed.
Data Sheet U10101EJ4V0DS
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