Jnc: Often used for broadcast lines on a bus

2025-07-28T07:07:53Z

Often used for broadcast lines on a bus

← Older revision		Revision as of 07:07, 28 July 2025
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	It connects together the outputs of the gates which produce the signals which are to be ORed together; a pull-up [[resistor]] to the supply [[voltage]] completes the 'gate'. Since [[transistor-transistor logic\|TTL]] gates produce low outputs by sinking [[current]] to [[ground]] (drawing it ''into'' the gate through the output, seemingly paradoxically), any of the gates in the wired-OR can force the output low by turning on.		It connects together the outputs of the gates which produce the signals which are to be ORed together; a pull-up [[resistor]] to the supply [[voltage]] completes the 'gate'. Since [[transistor-transistor logic\|TTL]] gates produce low outputs by sinking [[current]] to [[ground]] (drawing it ''into'' the gate through the output, seemingly paradoxically), any of the gates in the wired-OR can force the output low by turning on.

			(This method is often used to implement [[broadcast]] lines on a [[bus]].)

	Similarly, this technique allows the creation of so-called '''wired-AND''' in [[positive logic]]; if any of the inputs to the 'AND' is low, it force the output low - i.e. a logical AND.		Similarly, this technique allows the creation of so-called '''wired-AND''' in [[positive logic]]; if any of the inputs to the 'AND' is low, it force the output low - i.e. a logical AND.

	[[Category: Technology]]		[[Category: Technology]]

Jnc: brief but complete

2022-02-21T00:27:20Z

brief but complete

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'''Wired-OR''' refers to a common technique which uses no active devices to perform the [[logic]] function; it wires together the outputs of multiple [[open collector]] [[gate]]s to do it, using [[negative logic]].

It connects together the outputs of the gates which produce the signals which are to be ORed together; a pull-up [[resistor]] to the supply [[voltage]] completes the 'gate'. Since [[transistor-transistor logic|TTL]] gates produce low outputs by sinking [[current]] to [[ground]] (drawing it ''into'' the gate through the output, seemingly paradoxically), any of the gates in the wired-OR can force the output low by turning on.

Similarly, this technique allows the creation of so-called '''wired-AND''' in [[positive logic]]; if any of the inputs to the 'AND' is low, it force the output low - i.e. a logical AND.

[[Category: Technology]]

Wired-OR - Revision history

Jnc: Often used for broadcast lines on a bus

Jnc: brief but complete