Questions and Answers
What types of operations can the ALU perform?
What is the role of the instruction decoder?
Which component temporarily stores the results of arithmetic and logic operations?
What function does the oscillator serve in the timing and control unit?
Signup and view all the answers
What is the purpose of the SIM and RIM instructions?
Signup and view all the answers
What is the primary function of the accumulator in the ALU?
Signup and view all the answers
Which register is specifically designed to maintain the address of the last data entered into the stack?
Signup and view all the answers
Which of the following statements is true regarding the General Purpose Registers in Intel 8085?
Signup and view all the answers
What occurs to the Program Counter (PC) after the execution of an instruction?
Signup and view all the answers
How does the Incrementer-Decrementer function in relation to the Stack Pointer or Program Counter?
Signup and view all the answers
Study Notes
Accumulator
- An 8-bit register that holds data for processing by the Arithmetic Logic Unit (ALU).
- Stores results of operations and is also referred to as the A register.
- Connected to an 8-bit internal data bus for data transfer.
Temporary Register
- Receives data from external memory or general-purpose registers for the ALU.
- Supplies one input to the ALU while the other input is from the accumulator.
- Used for storing operands in arithmetic and logic operations.
General Purpose Registers
- Six 8-bit general-purpose registers: B, C, D, E, H, and L.
- Registers can be used individually or combined as pairs (BC, DE, HL) for 16-bit operations.
- HL register pair typically serves as a 16-bit memory pointer.
Stack Pointer (SP)
- A 16-bit register that maintains the address of the last byte entered into the stack.
- Stack is a reserved area of RAM for temporary data storage.
- Decrements on data entry and increments on data retrieval.
Program Counter (PC)
- A 16-bit memory pointer that sequences instruction execution.
- Points to the address of the next instruction.
- Increments by one after executing an instruction to indicate the next location.
Incrementer-Decrementer
- Can add or subtract one from the contents of the stack pointer or program counter.
Arithmetic and Logic Unit (ALU)
- Executes arithmetic (addition, subtraction) and logic operations (AND, OR, XOR) on 8-bit data.
- Inputs to the ALU are from the accumulator and the temporary register.
- Stores results back in the accumulator.
Flags
- Composed of five individual flip-flops indicating statuses after arithmetic and logic operations.
Instruction Register and Decoder
- An 8-bit register that fetches and loads instructions from memory.
- Instruction decoder decodes contents to determine operation execution and directs the timing and control unit.
Timing and Control Unit
- Contains an oscillator generating two-phase clock signals (CLK and CLK bar) for synchronization of registers.
- The controller sequencer is micro-programmed and contains ROM for storing micro-routines needed for instruction execution.
Interrupt Control
- Manages temporary interruptions for input/output (I/O) device requests.
- The main program execution is halted to process interrupt signals for data input.
Serial I/O Control
- Manages serial data input and output for I/O devices.
- Data enters the 8085 microprocessor through SID (serial input data) and exits through SOD (serial output data).
- SIM and RIM instructions facilitate serial-parallel conversion for serial I/O operations.
Address Buffers
- Contents of the stack pointer or program counter can be loaded into address buffers.
- Outputs direct external address and address data buses, connecting memory and I/O chips to the CPU.
- Enables the CPU to send addresses for desired data to memory or I/O devices.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the functions and characteristics of accumulators and temporary registers in computer architecture. This quiz covers their roles in the Arithmetic Logic Unit (ALU) and their connection to the internal data bus. Test your knowledge and understanding of these essential components of a computer system!