spi between 16f877a and 16f877a
16f877 can have communication with each other through the SPI module, to be precise through the SPI (serial perepheral interface).
One controller acts as a master and the other as a slave. All the communication is controlled by master. It will decide when to transmit and when to recieve from the other MCU. This method is very easy and can be implemented just by reading the data sheet. Also u need to keep in mind that only the master drives the clk line!