INTEL Microprocesser 8085

SECONDARY MEMORY: The magnetic memory is used as secondary and backup memory. It is employed for bulk storage of programs, data and other information. It has much larger capacity than main memory....

ROM § ROM stands for Read only memory. § It is nonvolatile memory, i.e., the information stored in it is not lost even if the power supply goes off. § It is used for permanent storage of information. §...

RAM The read and write memory (R/W) memory of a computer is called RAM. The users can write information into RAM and read information from it.  It possesses random access property. In a random...

PRIMARY MEMORY: It stores programs and data which are currently needed by the CPU. The semiconductor memory is employed as the main memory of the computer. As the CPU employs semiconductor technology...

Status code for Intel 8085 RD (OUTPUT): It is a control signal sent by the microprocessor to control read operation. The selected memory or I/O device is read when RD is low. WR (OUTPUT): It...

PIN CONFIGURATION OF INTEL 8085 A8-A15 (OUTPUT): These are address lines. They form the address bus. They carry 8 MSBs of memory address or 8 bits of I/O address. AD0-AD7 (INPUT/OUTPUT):...

Stack Pointer (SP) The stack pointer is also a 16-bit register used as a memory pointer. It points to a memory location in R/W memory, called the stack. The beginning of the stack is defined by...

Program Counter (PC) This 16-bit register deals with sequencing the execution of instructions. This register is a memory pointer. Memory locations have 16-bit addresses, and that is why this is...

Status Register (or Flag register).  A flag register contains a number of flags either to indicate certain conditions arising after arithmetic and logical operations or to control certain operations....

Accumulator The accumulator is an 8-bit register that is a part of arithmetic/logic unit (ALU). This register is used to store 8-bit data and to perform arithmetic and logical operations. The result...

Registers §   Six general purpose 8-bit registers: B, C, D, E, H, L §   They can also be combined as register pairs to Perform 16-bit operations: BC, DE, HL §   Registers...

Control Bus §  Consists of various lines carrying the control signals such as read / write enable, flag bits. §  The Control Bus carries control signals partly unidirectional, partly bi-directional. § ...

Address Bus §   Consists of 16 address lines: A0 – A15. §   Operates in unidirectional mode: The address bits are always sent from the MPU to peripheral devices, not reverse. § ...

Data Bus §  Consists of 8 data lines: D0 – D7. §  Operates in bi-directional mode: The data bits are sent from the microprocessor unit to peripheral devices, as well as from the peripheral...

A microprocessor is a programmable digital electronic circuit that incorporates the functions of a central processing unit on a single semiconducting integrated circuit. Microprocessor (Intel 8085)...