1 VCC power_in
2 CLK/IN1 input
3 IN2 input
4 IN3 input
5 PD/IN4 input
6 IN5 input
7 IN6 input
8 GND power_in
9 IN7 input
10 IN8 input
11 IN9 input
12 IN10 input
13 IN11 input
14 GND power_in
15 GND power_in
16 IN13 input
17 IO14 bidirectional
18 IO15 bidirectional
19 IO16 bidirectional
20 IO17 bidirectional
21 IO18 bidirectional
22 GND power_in
23 IO19 bidirectional
24 IO20 bidirectional
25 IO21 bidirectional
26 IO22 bidirectional
27 IO23 bidirectional
28 VCC power_in