Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

POSTPONED

IEC

IEC postponed output qualifier

The postponed output qualifier is a small right-angle mark inside the outline next to an output. It indicates that the output changes when the input that initiated the change, typically the C input, returns to its initial external state. It identifies pulse-triggered or master-slave flip-flops and data lock-out types.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: Angle mark inside the outline next to the output. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier.

A distinction that matters

An edge-triggered flip-flop has a dynamic C input and no postponed output mark.

Full reference

1J 1K

IEC

IEC pulse-triggered (master-slave) JK flip-flop

A pulse-triggered or master-slave JK flip-flop is drawn with a static C1 input and postponed output marks at Q and its complement. The data must be set up before the clock pulse starts and held while C1 is active; the outputs change when C1 returns to its initial level.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: JK bistable with static C1 and postponed-output marks. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier.

A distinction that matters

The edge-triggered JK flip-flop has a dynamic C1 and no postponed marks.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.