Table of Contents
What does AVR command do in assembly program?
AVR uses a Harvard architecture which is an architecture with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining. This means that while one instruction is being executed, the next instruction is pre-fetched from the program memory.
How many registers are there in AVR?
The three registers available in AVR microcontroller are as follows: DDRx register. PORTx register. PINx register.
What are AVR registers?
All information in the microcontroller, from the program memory, the timer information, to the state on any of input or output pins, is stored in registers. Registers are like shelves in the bookshelf of processor memory.
What is stack in AVR?
The Stack Pointer is a special register in I/O Memory that points to space allocated in SRAM, referred to as The Stack. The Stack is used to temporarily store register values and return addresses when subroutines are called. The Stack Pointer is a 16-bit register defined in include files as SPH and SPL.
What are the different addressing modes in AVR?
AVR Addressing Modes
- Register Direct, with 1 and 2 registers.
- I/O Direct.
- Data Direct.
- Data Indirect.
- Code Memory Addressing.
What is SPH in AVR?
SPH holds the most significant address byte, SPL the least significant. This is only true, if the AVR type has more than 256 byte SRAM. If not, SPH is undefined and must not and cannot be used.
What is AVR ports?
In AVR microcontroller family, there are many ports available for I/O operations, depending on which family microcontroller you choose. For the ATmega32 40-pin chip 32 Pins are available for I/O operation. The four ports PORTA, PORTB, PORTC, and PORTD are programmed for performing desired operation.
Where is the program stored in AVR?
The AVR executes programs stored in program memory only. code memory type specifier is used to refer to program memory.
Why addressing modes are used?
An addressing mode specifies how to calculate the effective memory address of an operand by using information held in registers and/or constants contained within a machine instruction or elsewhere.
What is indirect program memory addressing?
Indirect addressing is a scheme in which the address specifies which memory word or register contains not the operand but the address of the operand.
What are the features of AVR?
Which are the Features of AVR Microcontroller?
- Multifunction.
- Multiple internal oscillators.
- Flash memory up to 256 KB.
- Internal data EEPROM up to 4 KB.
- Internal SRAM up to 16 KB.
- Two timers are 8 bit, and one timer is 16 bit.
What are the functions of ATmega128?
ATmega128 can perform a number of functions on a single chip. Large memory space with more number of pins interface put this device ahead of other controllers available in the AVR community. Following are the major functions associated to this tiny module. Atmega128 comes with four timers i.e. two 8-bit and two 16-bit timers.
What is the instruction manual for 8-bit AVRS?
This manual gives an overview and explanation of every instruction available for 8-bit AVR®devices. Each instruction has its own section containing functional description, it’s opcode, and syntax, the end state of the status register, and cycle times.
What are the limitations of AVR microcontrollers with I/O Direct addressing?
Note: Some AVR microcontrollers have more peripheral units than can be supported within the 64 locations reserved in the opcode for I/O direct addressing. The extended I/O memory from address 64 and higher can only be reached by data addressing, not I/O addressing.
What are the memory types used in atmeag128?
Two memory types are mainly used in ATmeag128 named as Program Memory (Flash Memory) and SRAM memory where former makes use of a single pipelining for the execution of the instructions and later is a volatile memory mainly depends on the power supply source.