Neo Geo custom chip NEO-D0 - what does it do?

Regarding the surface mounted custom chip NEO-D0 near the crystal - besides providing various clock signals, does it do anything else?

Does it have anything to do with the sound circuit (besides providing the clock for the Z80 ) ?

Ta

System clocks... clock for 68K... both system reset lines... chip selects for the sound RAM and Yamaha 2610 sound IC...

Many thanks.