In my application i need to use a common line shared between two peripherals, i have to indicate to the devices whenever the bus is free or not, hence i can't have push-pull output where the output is either 0 or 1 , as these states are generally used for data transmission.
Instead i would prefer to have a open drain scenario, where the output "floats", to indicate to the device that the bus is free.
Now to achieve this, i want to use a transmission gate, where the third state(open) is used by controlling the enable pin, if enable is on (the normal 2- state logic, 0 or 1 where input flows to output), else the output pin floats.
Now my question is , if this setup is similar to the the way 3 state logic is used in microcontrollers/microprocessors , where an internal pull up resistor controls , the logic of the output pin , if it is different then in what way does it differ ?
Also have i missed something, do i have to read anything more to complete my understanding ??
The Line is driven by a totem pole output, where only logic 1(5v), and Logic 0(0v) , signals are driven.