Worksheets8051 Addressing Modes: Immediate, Register, and Direct
Total questions: 10
Worksheet time: 5mins
Which 8051 addressing mode uses a '#' symbol to indicate that the operand is a constant embedded in the instruction?
Indirect addressing with '#'
Direct addressing with '#'
Register addressing without '#'
Immediate addressing with '#'
In 8051 register addressing, which statement is correct about allowed transfers?
A to R0–R7 is allowed
R0 to R7 memory is allowed
RAM-to-RAM register move allowed
Any register pair move allowed
In the 8051 microcontroller, which addressing mode allows access to the internal RAM directly?
Indirect addressing mode
Immediate addressing mode
Direct addressing mode
Register addressing mode
Which instruction correctly loads accumulator A with the immediate hexadecimal value 35H?
MOV #A,35H
MOV 35H,#A
MOV A,35H
MOV A,#35H
When accessing sequential data in memory, which addressing mode is optimal for modifying the pointer during each iteration and why?
Indirect addressing, address held in register
Direct addressing, address literal in code
Immediate addressing, data constant in code
Register addressing, source is accumulator
@ is used to indicate that the register is giving__________________________?
an address
an immediate value
starting address of an array
reset value
In the instruction MOVX A,@DPTR, what memory and addressing are involved?
External RAM via 16-bit DPTR
Internal RAM via R0 pointer
Code memory via A+DPTR
Internal ROM via direct byte
What takes place by the instruction MOVX A, @R0 or @R1 ?
To read data from external RAM
To write data to external RAM
To initialize external RAM
To delete data from external RAM
Which instruction type is used to fetch from a look-up table stored in code memory using a base+index?
MOV with direct byte
MOVC with A+DPTR
PUSH with DPTR
MOVX with DPTR
Given DPTR=0400H and A=05H, what address is read by MOVC A,@A+DPTR?
0005H in code memory
0405H in code memory
0005H in internal RAM
0405H in external RAM
