Microprocessors

Inside the CPU, from 8085 to ARM. How processors work and connect to the world: CPU architecture and performance, the classic 8085 and 8086 with assembly programming, the ARM architecture, interrupts, and memory and peripheral interfacing.

• Processor Architecture — How a CPU works inside: the fetch–decode–execute cycle, ALU, registers, program counter, control unit and buses; von Neumann vs Harvard architectures; CISC vs RISC; clock rate, CPI and MIPS; pipelining and hazards; and the memory hierarchy with caches.
• 8085 Microprocessor — The Intel 8085 is the classic 8-bit teaching processor. Learn its architecture (accumulator, registers B–L, flags, SP, PC), multiplexed address/data bus, pin functions, addressing modes, instruction groups, T-states and machine cycles, assembly programming and software delay loops.
• 8086 Microprocessor — The 16-bit 8086 introduced the x86 architecture still used in PCs. Learn the BIU/EU split with instruction queue, segment registers and physical address calculation, general and pointer registers, flags, addressing modes, minimum/maximum modes, and 8086 assembly with MASM syntax.
• ARM Architecture — ARM processors power almost every phone and most microcontrollers. Learn the ARM RISC philosophy, profiles (Cortex-A, R, M), register file (R0–R15, CPSR/xPSR), load/store architecture, Thumb-2 instructions, condition codes, the AAPCS calling convention, pipelines, and ARM assembly examples.
• Interrupts — Interrupts let hardware get the processor's attention immediately. Learn polling vs interrupts, the interrupt sequence (save context, vector, ISR, return), vectored and priority interrupts, maskable vs non-maskable, the 8085/8086 schemes, the ARM NVIC, latency, nesting, and writing safe interrupt service routines.
• Memory & Peripheral Interfacing — Connecting a processor to memory and I/O. Learn memory types (SRAM, DRAM, ROM, Flash, EEPROM), address decoding and memory maps, chip capacity and expansion, memory-mapped vs isolated I/O, wait states and access timing, programmable peripherals (8255, 8253/8254, 8251, 8259), and DMA.