The pin is being set using direct port manipulation. The register that contains the pin states for a given port is called PORTC. The DATA_1 and DATA_0 macros are diddling one pin in that port.
The pin is being set using direct port manipulation. The register that contains the pin states for a given port is called PORTC. The DATA_1 and DATA_0 macros are diddling one pin in that port.