8051 timers and registers Is it necessary to use both TL0 and TL1 to start Timer 0?

Introduction / Context:
The 8051 provides two timers: Timer 0 and Timer 1. Each timer uses its own pair of high and low byte registers. This question checks recognition of which registers belong to which timer.

Given Data / Assumptions:

• Timer 0 uses TH0 (high) and TL0 (low).
• Timer 1 uses TH1 (high) and TL1 (low).
• TMOD configures modes; TCON starts/stops timers via TR0/TR1.

Concept / Approach:
Starting Timer 0 requires configuring TMOD for Timer 0 and setting TR0 in TCON. Only TH0 and TL0 are involved for count/reload depending on mode; TL1 is unrelated and belongs to Timer 1.

Step-by-Step Solution:

Verification / Alternative check:
Examine SFR map: TL0/TH0 at distinct addresses from TL1/TH1; no cross-dependency exists.

Why Other Options Are Wrong:

• True: Incorrect; Timer 0 does not require Timer 1 registers.
• Only in auto-reload / external clock: These modes still use only TH0/TL0.

Common Pitfalls:
Confusing the two timers or mixing their SFRs when writing initialization code.

Final Answer:
False — Timer 0 uses TH0 and TL0 only.