Digital clock timing: required division of the basic frequency In a standard digital clock application, to generate the “tick” that advances the seconds counter, the basic frequency must be divided down to what rate?

Introduction / Context:
Whether your time base is the mains frequency (50/60 Hz) or a crystal oscillator (for example, 32.768 kHz), a digital clock requires a precise 1 Hz pulse to advance the seconds counter once per second.

Given Data / Assumptions:

• Seconds increment once each second.
• Higher-frequency references must be divided (prescaled).
• Stable division ensures accurate timekeeping.

Concept / Approach:
Use a frequency divider so that the output is 1 tick per second. For a 60 Hz input, divide by 60; for 32.768 kHz, divide by 32,768. The exact divider topology may use cascaded binary or BCD counters in HDL.

Step-by-Step Solution:

Verification / Alternative check:
Simulate and measure output period; confirm 1 second between rising edges.

Why Other Options Are Wrong:

• 60 Hz/100 Hz/1000 Hz correspond to upstream references or debounce rates, not the seconds tick.

Common Pitfalls:
Neglecting oscillator tolerance and temperature; consider calibration if needed.

Final Answer:
1 Hz.