What is the control word for 8255 PPI to set bit PC3?

To set bit PC3 on the 8255 Programmable Peripheral Interface (PPI), you need to configure the control Word appropriately. The control Word should be set to 80H (in hexadecimal), which configures Port C in mode 0 and sets PC3 as an output. This allows you to control PC3 by writing a logic high (1) to it. To ensure that PC3 is set, you would write a value of 8 (for PC3 high) to Port C after setting the control Word.