How does microprocessor differentiate between data and instruction code?

Answer 1

i) Instruction code deals only with mnemonics and its corresponding opcode but data code refers to your data like 10h which is always of 8 bits or a particular address say 8080h which is of 16 bits.

ii) Data is your input to the instruction but an opcode is native to your machine.

iii) Data is user specific instruction while opcode is machine specific instruction

iv) You can alter data code but you cannot modify an instruction opcode.

Answer 2

i) Instruction code deals only with mnemonics and its corresponding opcode but data code refers to your data like 10h which is always of 8 bits or a particular address say 8080h which is of 16 bits.

ii) Data is your input to the instruction but an opcode is native to your machine.

iii) Data is user specific instruction while opcode is machine specific instruction

iv) You can alter data code but you cannot modify an instruction opcode.

Answer 3

The 8085 (sort of) differentiates between data and instructions with the S0 and S1 status pins. Considering IO/M- to be low (memory only), S0 is high on opcode fetch and memory write, and low on memory read, while S1 is high on operand fetch and memory read, and low on memory write. (You need to decode them to see a clear picture.)

However, on a multiple byte instruction, S0 is high only on the first byte, and it is low on subsequent bytes, so it is a bit more difficult to tell the difference. If you really needed to know, you would need to track the memory cycles starting with opcode fetch, knowing the opcode meanings, and noting the immediate instruction bytes as opposed to anything else.

Answer 4

Instruction code deals only with mnemonics and its corresponding opcode but data code refers to your data like 10h which is always of 8 bits or a particular address say 8080h which is of 16 bits.

In short data is your input to the instruction but an instr. is native to your machine.

Data- user specific

instr.-machine specific

you can alter data code but not modify an instruction opcode.

Answer 5

It doesn't as can be witnessed if you load the wrong value in an instruction address register, the CPU will try to execute anything in the memory space it is looking at.

The only differentiation is at load time. The loader gets the start address for the execution and initializes the CPU to that. After that the code must be proper and not misdirect the CPU.

To the CPU the contents of a byte of memory indistinquishable. It is just program execution and path that keeps the CPU executing code and not data

Answer 6

(1)Instruction code deals only with mnemonics and its corresponding opcode but data code refers to your data like 10h which is always of 8 bits or a particular address say 8080h which is of 16 bits.

(11) Data is your input to the instruction but an opcode is native to your machine.

111. Data is user specific instruction while opcode is machine specific instruction

1v) You can alter data code but you cannot modify an instruction opcode.

Answer 7

opcode is the opration code which is to be perform n oprand can be data or address on which that operation is to be perform by opcode