48μPD170627. ARITHMETIC LOGIC UNIT (ALU) BLOCK7.1 OVERVIEWFig. 7-1 is an overview of the ALU block.As shown in Fig. 7-1, the ALU block consists of the ALU, temporary storage registers A and B, programstatus word, decimal conversion circuit, and data memory address controller.The ALU performs arithmetic and logic operations on the 4-bit data in the data memory and performsdiscrimination, comparison, rotation, and transfer.Fig. 7-1 Overview of the ALU BlockData memoryData busProgram statuswordAddresscontrollerTemporarystorageregister ATemporarystorageregister BIndexing memorypointerDetecting a carry,borrow, or zeroSetting decimalcalculation or resultstorageALU• Arithmetic operation• Logic operation• Bit discrimination• Comparativediscrimination• Rotation• TransferDecimal conversion
