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

IEC

IEC mode dependency (M)

M dependency is used where a device has several operating modes. When an Mm input is at its internal 1 state, inputs and outputs labelled m have their normal effect; otherwise they are disabled. Mode inputs are often produced from two select lines by binary grouping, giving M0 to M3.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: Mode inputs labelled Mm, often produced by binary grouping, with affected terminals labelled m. 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

A (address) dependency selects among arrays of identical elements; M selects operating modes of one element.

Full reference

SRG4

IEC

IEC bidirectional (universal) shift register

A universal shift register is drawn as an SRG element with two mode-select inputs grouped to produce modes 0 to 3. The clock label shows shift right under one mode and shift left under another, while data inputs are labelled with their mode and control numbers, such as 1,4D for serial right input and 3,4D for parallel load.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: SRGm element with mode inputs selecting shift right, shift left and parallel load. 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

A single-direction SRG register has no mode inputs and shifts only one way.

Full reference

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