8051 Timers — Loading TH0 Which instruction correctly loads the immediate value 35H into the high byte of Timer 0 (TH0)?

Introduction / Context:
Timer registers in the 8051 are split into THx (high) and TLx (low) bytes. Correct immediate loading syntax ensures predictable starting values for counting or timing operations.

Given Data / Assumptions:

• Target register is TH0 (timer 0 high byte).
• Value to load is 35H.
• Assembler syntax uses # for immediate data.

Concept / Approach:
Immediate moves use the form MOV destination, #immediate. TH0 is a valid SFR symbol. Therefore the correct instruction is MOV TH0, #35H.

Step-by-Step Solution:
1) Select the register: TH0.2) Use immediate notation: prefix with #.3) Write the instruction: MOV TH0, #35H.

Verification / Alternative check:
Assembler reference confirms that omitting # interprets the operand as a direct address, not a literal, which is not intended here.

Why Other Options Are Wrong:

• MOV TH0, 35H: Treats 35H as a direct address, not a literal value.
• MOV T0, #35H and MOV T0, 35H: T0 is not a valid 8051 SFR name for the high byte; the correct symbol is TH0.

Common Pitfalls:
Forgetting the # for immediate data and mixing up TH0 with TL0.

Final Answer:
MOV TH0, #35H