17P012 datasheet(57/320 Pages) RENESAS

57 / 320 page

µPD17012, 17P012

Data Sheet U10101EJ4V0DS

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.

17P012 Datasheet(PDF) 57 Page - Renesas Technology Corp