Dependency notation

The dependency notation is a method to characterize the function of circuit symbols of digital components in electronics . The dependency notation is defined in the standard DIN EN 60617-12 / IEC 60617-12 Graphic symbols for circuit diagrams - Part 12: Binary elements . The function of complicated components can be clearly displayed using the dependency notation. The previous standard DIN 40900-12 already replaced the round and triangular symbols with rectangular ones.

In the designation, a code letter is used on the one hand, which indicates the function of the connection, as well as key figures, via which the dependencies are defined. A distinction is made between inputs and outputs as well as controlling and controlled connections. If there are multiple dependencies, the individual dependencies are separated by commas. If the dependencies are independent of each other, separation with a slash is also possible.

Multiple connections can be combined with a curly bracket to form a single “variable”, the dual value of which describes which connections are controlled. This is what the notation means

{\ displaystyle \ left. {\ begin {matrix} 0 \\ 1 \ end {matrix}} \ right \} \, G \, {\ frac {0} {3}}}

,

that the connections 0 and 1 are internally AND-linked and should be understood as a binary number, whereby the binary number represents the values 0 to 3, whereby the two inputs function as if they were implemented as four inputs (G0, G1, G2 and G3). The fraction line therefore indicates a range.

A line above a variable means that the value of the variable is negated. In addition, if necessary, additional letters can be introduced if this makes it easier to remember or understand better (e.g. D for data).

A plus sign (+) after a key figure means that the corresponding variable (or the input) causes an increment if the variable noted in front of it is one. A minus sign (-) causes a decrement . For example, this means that the input is a clock input (clock; variable 1) that increments (the value of a counter) when a one is applied to input 0 and decrements when a zero is applied to input 0. 0+/0-/C1

Identification letters

The following letters are used in the dependency notation:

book letter	meaning	description
G	AND	AND link
V	OR	OR link (OR)
N	XOR, Negate	Exclusive-or link or negation
Z		unchanged transmission
C.	Control	control
S.	set	Put
R.	Reset	Reset to default
EN	Enable	turn on
M.	Fashion	mode
L.	Load	load
T	Toggle	Switch
A.	Address	address
CT	Content	(Counter / memory) content

Examples

Forms of representation of OR gates
a = e ₀ ⋁ e ₁	Dependency notation (with amplifier output)	Dependency notation

Forms of representation of AND gates
a = e ₀ ⋀ e ₁	Dependency notation (with amplifier output)

Forms of representation of exclusive-or gates
a = e ₀ ⊻ e ₁	Dependency notation (with amplifier output)	Dependency notation

Forms of representation of multiplexers
1-MUX	2-MUX	Two 1-MUX with common control

other
Combined AND and OR gate a = (e ₀ ⋀ e ₂ ) ⋁ e ₁