Media Technology Systems AMX 0.2 - Manual (Page 16)

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4.3 Digital&Signal&processing.&
!
The!AMX0.2CN!uses!the!CS496112!chipset,!which!allows!for!>100MIPS!of!digital!signal!
processing!(DSP).!!
4.3.1 Automatic&Microphone&Mixer&
4.3.1.1 Overview&
!
Before!proceeding!to!the!DSP!schematic,!it!will!be!necessary!to!understand!how!the!
Automatic!Microphone!mixer!device!works.!The!input!section!of!the!AMX0.2CN!is!
shown!below!(Figure 4-2)!and!has!inputs!1L8!as!audio!in,!outputs!1L8!as!gated!audio!out,!
inputs!9L12!as!link!signals!in!and!output!9!as!link!signal!out.!
!
!
Figure 4-2: AMX0.2CN input section showing Automatic Microphone Mixer device !
!
The!automatic!mixer!device!does!not!actually!perform!any!mixing.!The!automatic!mixer!
is!a!set!of!parallel!gates!to!be!connected!between!microphone!input!signals!and!a!
manual!mixer.!This!system!of!gates!automatically!selects!the!appropriate!channels!that!
should!be!allowed!to!pass!to!the!mixer.!
!
Selection!is!based!on!signal!level!at!the!input,!overall!audio!level!for!the!system,!priority!
level!assignment!and!configured!maximum!open!mic!constraints.!The!automix!device!
features!the!capability!to!receive!link!status!inputs!from!other!automix!devices,!combine!
this!information!from!the!multiple!sources!and!local!status!and!produce!operational!
parameters!and!a!Master!link!output!which!can!be!fed!back!to!the!other!automix!devices!
allowing!them!to!all!operate!together!based!on!common!a!common!understanding!of!
the!system!state.!
!
The!Automatic!mixer!features!gating!and!priority!logic!and!facilities!for!linking!with!
other!automatic!mixer!devices.!!The!master!link!output!conveys!Number!of!Open!Mics!
(NOM),!priority!and!background!level!information!for!the!system.!The!master!link!
output!is!generated!based!on!the!link!input!signals!received!from!other!mixers!and!state!