Support for PISO (Parallel In - Serial Out) Shift Register such as 74HC165

[hamitron]

PISO is essentially the reverse of SIPO used by the 74HC595, it allows you to gather a large number of inputs, like buttons and transmit it serially.

This article talks about PISO registers
https://learn.sparkfun.com/tutorials/shift-registers