View idt74fst163214pv-tl datasheet:

IDT74FST163214PV-TL IL08 C-MOS 12-BIT 3:1 MUX/DEMUX SWITCH —TOP VIEW— INPUT S0 - S2 : SELECT LINES S0 IN 1 56 S1 IN 1A1 I/O 2 55 S2 IN INPUT/OUTPUT 1A1- 12A1 : BUS A1 1B3 I/O 3 54 1B1 I/O 1B1 - 12B1 : BUS B1 2A1 I/O 4 53 1B2 I/O 1B2 - 12B2 : BUS B2 2B3 I/O 5 52 2B1 I/O 1B3 - 12B3 : BUS B3 3A1 I/O 6 51 2B2 I/O 3B3 I/O 7 50 3B1 I/O 1 OF 12 CHANNELS 2 54 1A1 1B1 8 GND GND 49 4A1 I/O 9 48 3B2 I/O 3 1B3 4B3 I/O 10 47 4B1 I/O 53 1B2 5A1 I/O 11 46 4B2 I/O 5B3 I/O 12 45 5B1 I/O FLOW CONTROL 1 6A1 I/O 13 44 5B2 I/O S0 56 S1 6B3 I/O 14 43 6B1 I/O 55 S2 7A1 I/O 15 42 6B2 I/O 7B3 I/O 16 41 7B1 I/O S2 S1 S0 A1 FUNCTION 17 VDD 40 7B2 I/O 0 0 0 HI-Z DISCONNECT 0 0 1 B1 A1 TO B1 8A1 I/O 18 39 8B1 I/O 0 1 0 B2 A1 TO B2 19 G