PE2-1.5 Sequential CMOS Logic
You can design static latches and registers, MUX-based latches, static SR flip-flops and master-slave edge triggered registers, and describe dynamic latches and registers.
The master-slave register is the structure almost every synchronous chip is clocked by, and its two-phase operation is what makes edge triggering possible from level-sensitive parts. Static versus dynamic is the same bargain as in the previous unit: static holds its value indefinitely at the cost of transistors, dynamic is small and must be refreshed before the charge leaks away. Setup and hold time appear here as consequences of the internal structure rather than as datasheet numbers.
Work through these
Static latches and registers
The circuits that remember, which is where combinational design becomes sequential. Cross-coupled inverters are the underlying idea in every one of them.
MUX based latches
Building a latch from the switch structure at the end of the previous topic. It is compact and it is what most standard cell libraries actually contain.
Static SR flip-flops
The classic storage element and its forbidden input combination. Worth knowing as the ancestor of everything else here.
Master-slave edge triggered register
Two latches in series so the output changes only on an edge. It is the flip-flop every synchronous design is built from.
Dynamic latches and registers
The storage that relies on charge rather than feedback, which is smaller and leaks. It sets a minimum clock frequency, which is an unusual constraint.
Setup and hold time as consequences of latch structure
Where timing requirements come from: they fall out of the latch structure rather than being imposed. Understanding that makes timing analysis reasoning rather than rule-following.
Sign in to keep your progress.
Free resources
We haven't checked most of these for screen reader use yet.
Links last checked 30 Aug 2026.
Stuck here?
Ask a mentor. A real person answers, and they can see exactly which topic you're on. Usually within a couple of working days.
Checking your session…
Topics shown in module order.