Understanding three state logic

[gkmaia]

I need some help to understand a circuit.

SRCLR and RCLR are always at 5V so always HIGH.

If IC 2162 pin 6 is LOW then the voltage after R2168 is grounded as it flows through D2165 towards ground by three state pin 6 of IC 2162.

This is what brings IC's 2165 pin 12 to LOW.

Both D2165 and D2166 stop current from flowing from processor and IC2162 into RCK so they can IC2162 and PROCESSOR do not send each other current.

Is the assessment correct?

[ledtester]

The diodes and resistor form a simple AND gate:

https://electronicsarea.com/or-and-and-logic-gates-with-diodes/

If the cathode of either diode is LOW then current flows through the resistor bringing RCK LOW (or around 0.6V).

If both cathodes are HI then RCK is pulled high by the resistor.