Variable Access

This group specifies macros to access bits of a variable. More...

Macros
#define	IO_VAR_SET(var, bits, on, set)
	Set a set of variable bits. More...
#define	IO_VAR_GET(var, bits, on)
	Evaluates to a bit mask of logical states of a variable. More...

Detailed Description

This group specifies macros to access bits of a variable.

Their value lies in the seperation of encoded on state and logical on (1), as well as the safe bit masking.

Macro Definition Documentation

IO_VAR_GET

#define IO_VAR_GET	(		var,
			bits,
			on
	)

Value:

( \
        ((var) ^ ~(on)) & (bits) \
)

Evaluates to a bit mask of logical states of a variable.

Parameters

var	The variable to access
bits	A bit mask of the bits to select
on	A bit mask that defines the states which represent true

IO_VAR_SET

#define IO_VAR_SET	(		var,
			bits,
			on,
			set
	)

Value:

{\
        (var) &= ((set) ^ ~(on)) | ~(bits); \
        (var) |= ((set) ^ ~(on)) & (bits); \
}

Set a set of variable bits.

Parameters

var	The variable to set
bits	A bit mask of the bits to select
on	A bit mask that defines the states which represent true
set	Set logical values for the defined bits