UPD17073 NEC, UPD17073 Datasheet - Page 41

• Manufacturer Part Number: UPD17073
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER WITH HARDWARE FOR DIGITAL TUNING SYSTEM
• Manufacturer: NEC

7.2 Configuration and Function of Each Block
7.2.1 Functions of ALU
bit data as the instruction specified by the program.
7.2.2 Temporary registers A and B
7.2.3 Program status word
to 5.4 Program Status Word (PSWORD).
7.2.4 Decimal adjuster circuit
is converted into decimal numbers by the decimal adjuster circuit.
7.2.5 Address control circuit
7.3 ALU Processing Instructions
The ALU performs arithmetic operation, logical operation, bit judgment, comparison, rotation, and transfer of 4-
Temporary registers A and B temporarily stores 4-bit data.
These registers are automatically used when an instruction is executed and cannot be controlled by program.
The program status word controls the operations of the ALU and stores the status of the ALU. For details, refer
When the BCD flag of the program status word is set to 1 during an arithmetic operation, the result of the operation
The address control circuit specifies an address of the data memory.
Table 7-1 shows the operations of the ALU when each instruction is executed.
Table 7-2 shows the decimal adjusted data when a decimal operation is performed.
PD17072,17073
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