Definition of cascade in counter design “The term cascade means connecting the Q output of one flip-flop to the clock input of the next.” Determine whether this usage is acceptable in counter practice.

Introduction / Context:
“Cascading” counters or flip-flops is common in building larger modulus dividers. The word can refer to several chaining methods, but a classic usage is in ripple counters where one stage’s Q drives the next stage’s clock input. This question checks the validity of that definition.

Given Data / Assumptions:

• Ripple (asynchronous) counters often chain Q → CLK from stage to stage.
• Synchronous counters also cascade functionally but keep a common clock; their “cascade” uses carry/borrow or enable lines rather than Q → CLK.
• The statement focuses on one widely used cascading method.

Concept / Approach:
In many textbooks and datasheets, “cascade” in the specific context of ripple counters indeed means feeding the output of one flip-flop into the clock of the next to create divide-by-2, divide-by-4, etc. While the broader term can also describe synchronous expansion via carry chains, the stated definition is correct within the ripple-counter context.

Step-by-Step Solution:
Recognize ripple chaining: Q(n) drives CLK(n+1).This yields successive divide-by-2 stages (2^k overall).Thus, describing this as “cascading” is valid in standard practice.

Verification / Alternative check:
Examine application notes for classic TTL/CMOS counters (e.g., 74HC/T flip-flop chains); they use “cascade” terminology for Q-to-CLK connections in ripple configurations.

Why Other Options Are Wrong:
“Invalid” contradicts common usage. Restricting validity to synchronous or Johnson counters mischaracterizes the general term.

Common Pitfalls:
Assuming “cascade” only means ripple; forgetting that synchronous counters should share a common clock and use carry/enable for expansion.

Final Answer:
Valid