Dilshan R Jayakody’s Web Log

74181 is 4-bit arithmetic and logic unit introduced by Texas Instruments in March 1970 and it is known for being the first ALU in a single package. This chip is no longer in manufacturing but still, it is quite popular in CA ( computer architecture ) courses in many colleges. To test the behavior of this 4-bit ALU we decided to construct it on Altera MAX II CPLD. For this project, we choose EPM240T100C5 CPLD and logic design is implemented using Altera Quartus II . For logic design, we refer to Fairchild Semiconductor’s DM74LS181 datasheet. This setup is tested on basic EPM240 series development board with some mechanical switches and couple of LEDs. 74181 4-bit ALU test setup with the EPM240T100C5 development board. There are several test circuits available for 74181 ALU and our test setup is partially based on Electronics for Your (EFY) 1997 article. In another test setup, we use HEF4040 to drive, A and B operands of this ALU. The test setup attached to this article is t...

ALU (Arithmetic and Logic Unit) is a digital system that performs integer arithmetic and logical operations. In this post we introduce ATmega169 base ALU simulation using Proteus . This is 8bit ALU, and functionally it is similar to other entry level ALUs such as Motorola MC14581, 74LS181, etc. This unit can perform 80 arithmetic and logic operations and all these operations are listed in below of this post. schematic of ATmega169 base 8bit ALU simulation Firmware of this ALU is developed using AVR-GCC. While at the development we try to isolate firmware with platform as maximum as possible, because of that, this firmware can be modified to run on top of PIC , 8051 or MSP430 MCUs with minor set of changes.