Which addressing mode in the 8051 microcontroller allows data to be accessed through an address stored in a register (such as R0, R1, or DPTR)?
Register Indirect Addressing
In register indirect addressing, a register holds the address of the operand, not the operand itself. In the 8051, R0 or R1 point to internal RAM (e.g. MOV A, @R0) and DPTR points to external memory (e.g. MOVX A, @DPTR).
The “@” sign shows that the register’s contents are used as an address, which is exactly what the stem describes.
Immediate addressing puts the data in the instruction itself (MOV A, #25H); direct addressing gives the RAM address in the instruction (MOV A, 30H); indexed addressing adds A to DPTR or PC to read code memory (MOVC A, @A+DPTR), used mainly for look-up tables.
Hence, the answer is Register Indirect Addressing.
Similar Questions
A designer is developing an 8051-based embedded system that requires storage of a large amount of frequently changing data exceeding the internal RAM capacity, while keeping the program code unchanged. Which memory configuration is most suitable?
Which statement best describes the function of the MOV instruction in the 8051 microcontroller?
Important Questions from Microprocessors and Microcontrollers
Data and address bus width of 8085 microprocessor respectively are
How many bits are used in the data bus of 8051 ?
- Which of the 8051 ports need pull-up resistors to function as an I/O port?
How many bytes are used by the given data directive of the 8051 microcontroller?
DATA_1 DB "INDIA"
A. Microcontrollers are normally less expensive than microprocessors.
B. The 8051 microcontroller has three on-chip timers.
C. Mode 2 of 8051 timer is used to set the baud rate.
D. For the LCD to recognize information at the data pins as data, the register select (RS) pin must be set to low.
E. A driver must be placed between the micrcontroller and the stepper motor.
Choose the correct answer from the options given below:
