Notes with worthy tutorials
The instruction set or the instruction set architecture (ISA) is the set of basic instructions that a processor understands. The instruction set is a portion of what makes up an architecture. Read More: Define Instruction Set Architecture. What are the main objectives of ISA in computer systems. Two initial types of instruction set architecture are … Read more
Control unit co-ordinates the transfer of data between registers of CPU or microprocessor and ALU. Control unit serves the instructions for ALU. Along with this, control unit, as its name implies, controls every other parts of the machine, their co-ordinations, traffic etc.
Arithmetic and Logic Unit (ALU): Arithmetic and Logic Unit is a like a calculator to a computer. ALU performs all arithmetic operations along with decision making functions. In modern CPU or Microprocessors, there can be more than one integrated ALU to speed up arithmetical and logical operations, such as; integer unit, floating point unit etc. … Read more
Memory Mapped I/O and Isolated I/O are two methods of performing input-output operations between CPU and installed peripherals in the system. Memory Mapped I/O: Memory mapped I/O uses the same address bus to connect both primary memory and memory of hardware devices (registers). Memory and registers of I/O devices gets assigned values, thus when CPU … Read more
Addressing 5 ROM Chips, Each of 4 KB Using 74LS138 Decoder: The following diagram is representing the addressing of 5 ROM chips using 74LS138 where each chip is of 4 KB. Explanation: From the previously given figure 01 it can be found that the Chip Select (CS) of the 5 ROM chips has been attached … Read more
Interfacing the Microprocessor with Analog World: As computer used digital binary values whereas we have physical variables, a step by step process is used to convert the physical variable to binary data and again to physical variable. The figure is given below, (i) Transducer: A transducer is a device that … Read more
Controlling LEDs Using Microprocessor VIA 82C55A: Using the 82C55A, we can control LED lights. We can use the pins of one port to connect with one leg of the LEDs and pins of another port to connect rest of the legs. Then we can program the 82C55A to control the LEDs. It can be done … Read more
Purpose of Using Command Byte A: Command byte A is used select modes, working functions of the ports. So the importance of using command byte A is that we can define on which mode it will be working on and which port will be used for which function such as input or output. For example, … Read more
The given bit format is as follows, 7 6 5 4 3 2 1 0 1 0 0 0 0 0 1 0 Arrangement of Ports Due to Given Bit Format: So the arrangement will be, mode 0, port A and C as output, port B as input.
(i) Required Bit Format of command byte A: So the bit format will be 10010000. (ii) Required Bit Format of command byte A: So the bit format will be 1010×11×.