Class _ioa: General Purpose I/O definition

A class _ioa object is a single or a group of consecutive pins inside the same I/O port.

Instructions that do not produce C code:

The hw_bn() instruction returns the number of bits of an I/O definition:

#if (HW_ADDRESS((porta,3)) != -1) && (HW_BITS((porta,3)) != 1)
#  HWA is damaged!
#endif

For a group of consecutive pins, the hw_bp() instruction gives the position of the least significant bit:

#if (HW_ADDRESS((porta,3)) != -1) && (HW_POSITION((porta,3)) != 3)
#  HWA is damaged!
#endif

Configuration

Actions

configure:

hw | hwa( configure,   gpio0,
 
        [ function,    gpio, ]                                       // Default
 
        [ mode,        digital_input | digital_input_floating        // Default
                     | digital_input_pullup
                     | digital_input_pullup_when_awake
                     | digital_input_pullup_when_sleeping
                     | digital_output | digital_output_pushpull
                     | digital_output_when_awake | digital_output_pushpull_when_awake
                     | digital_output_when_sleeping | digital_output_pushpull_when_sleeping
                     | analog_input,
 
        [ pullup,      off
                     | when_awake
                     | when_sleeping
                     | on, ] );

// ALTERNATE_FUNCTION is a signal name, such as 'int0' or '(uart0,tx)'.
//
hw | hwa( configure,   (porta,0),
 
          function,    ALTERNATE_FUNCTION );

State

The instruction read returns the state of the I/O object:

uint8_t value = hw( read, gpio0 );

write:

hw( write, gpio0, value );

hwa( write, gpio0, value );

toggle:

hw( toggle, gpio0 ); //  Toggle one or several consecutive pins at once