Question about BDTR-2H chip

[chenron7]

Hello Im trying to understand how does the BDTR-2H chip works.
I understand that there are 3 delay units that make the reverb, but I dont understand how the circuit works, what is that Osc and how the 3 PT2399 are connected to each other. Can anyone help me ?

Thanks!

[cloudscapes]

Looks like OSC is just a schmitt trigger buffered by one of the PT2399's unused opamps and then into pin 6 (clock in).