Microprocessor 8085 Ppt By Gaonkar [hot] Jun 2026
Introduced by Intel in 1977 as an 8-bit processor. Microprocessor 8085 complete | PPTX - Slideshare
Bidirectional; transfers data between the CPU and memory/IO. Multiplexing: The lower 8 bits of the address bus ( ) are multiplexed with the data bus ( ) to save pins, controlled by the ALE (Address Latch Enable) Vardhaman College of Engineering Slide 6: Addressing Modes Gaonkar classifies 8085 instructions into five modes: Immediate: Data is part of the instruction (e.g., MVI A, 05H Data is moved between registers (e.g., Address is specified in the instruction (e.g., Data is pointed to by a register pair (e.g., Implied/Implicit: The operand is hidden in the opcode (e.g., - Complement Accumulator). Slide 7: Interrupts Hardware Interrupts: Highest priority, non-maskable. RST 7.5, 6.5, 5.5: Vectored and maskable. General purpose, maskable. Software Interrupts: RST 0 through RST 7. Slide 8: Serial I/O Control Uses two dedicated pins for serial communication: SID (Serial Input Data): Read using the instruction. SOD (Serial Output Data): Set using the instruction. GeeksforGeeks UNIT I – 8085 MICROPROCESSOR
The 8085 is housed in a 40-pin Dual In-line Package (DIP). One of its most notable architectural innovations is , which reduces the physical pin count. Address/Data Demultiplexing ( The lower 8 bits of the address bus ( ) and the 8-bit data bus ( ) are multiplexed onto the same pins ( During the first clock cycle ( T1cap T sub 1 microprocessor 8085 ppt by gaonkar
The 16-bit address is specified in the instruction (e.g., LDA 2000H ).
A 16-bit register pointing to a memory location in R/W memory called the "Stack," used for temporary data storage during subroutines. 2. Arithmetic and Logic Unit (ALU) The ALU performs execution data computing. It carries out: Introduced by Intel in 1977 as an 8-bit processor
Set to 1 if a carry is generated by bit D3 and passed to bit D4 during arithmetic. Used for BCD operations.
| Internal Block | Function | |:---|:---| | | Performs all the arithmetic (addition, subtraction) and logical (AND, OR, XOR) operations on data. | | Register Array | A set of general-purpose registers (B, C, D, E, H, L) used as temporary storage for data during program execution. | | Accumulator (A) | The primary register where one operand is placed for ALU operations and where the result is stored. | | Flag Register | An 8-bit register with five 1-bit flags (Sign, Zero, Auxiliary Carry, Parity, Carry) that indicate the status of the last ALU operation, used for making decisions in a program. | | Program Counter (PC) | A 16-bit register that always holds the address of the next instruction to be executed. | | Stack Pointer (SP) | A 16-bit register that points to the top of a stack in memory, used for temporarily storing data or return addresses. | | Timing and Control Unit | Acts as the brain's pacemaker, generating the necessary control signals to synchronize all operations and fetch-execute cycles. | | Instruction Register and Decoder | Holds the current instruction being executed and decodes it to determine the operation to be performed. | Software Interrupts: RST 0 through RST 7
pulse dropping down exactly when the address stabilizes on the bus lines. This visually reinforces the concepts of setup and hold times.
The PPTs based on Gaonkar's work are more than just lecture slides. They function as a dynamic study aid for students, offering a structured way to review complex topics like timing diagrams or interrupt priorities right before an exam. For educators, these presentations are a ready-made framework that can be customized for their own courses, ensuring they cover all critical aspects of the syllabus. By combining reading the textbook with reviewing these PPTs, students can solidify their grasp of the 8085, creating a robust foundation for studying more advanced processors in the future.