1)(2
		 3)(4
		 5)(6
		 7)(8
		 9)(10
		11)(12	CLK
		13)(14
		15)(16
		17)(18
		19)(20
		21)(22
		23)(24
		25)(26
		27)(28
		29)(30
		31)(32
		33)(34
FS		35)(36
		37)(38	DIN
		39)(40	DOUT

- PCM - Pulse-code Modulation -

PCM (Pulse-code Modulation) is a digital representation of sampled analog. On the Raspberry Pi it's a form of digital audio output which can be understood by a DAC for high quality sound.