Class _usia: Universal Serial Interface

A class _usia object is an USI.

Actions

configure:

hwa( configure,   USI,
 
     mode,        disconnected       // The USI is disabled
                | spi_master         // The USI acts as a SPI master
                | spi_slave          // The USI acts as a SPI slave
                | twi_master         // The USI acts as a I²C master
                | twi_slave,         // The USI acts as a I²C slave
 
     clock,       software           // Clocked by software
                | compare0           // Clocked by compare unit ? of counter 0
                | external_rising    // Clocked by external source rising edge
                | external_falling   // Clocked by external source falling edge
     );

read:

uint8_t byte = hw( read, usi0 );

write:

hw( write, usi0, 'A' );

trigger:

hw( trigger, usi0 );