#define	BIT_CLR(reg,bit)	do { (reg) &= ~ _BV(bit); } while (0)
#define	BIT_SET(reg,bit)	do { (reg) |=   _BV(bit); } while (0)
#define	BIT_TST(reg,bit)	(((reg) & _BV(bit)) != 0)

// I/O port manipulation macros
#define	DDR_CLR(p,b)		BIT_CLR(DDR  ## p, b)
#define	DDR_SET(p,b)		BIT_SET(DDR  ## p, b)
#define	PORT_CLR(p,b)		BIT_CLR(PORT ## p, b)
#define	PORT_SET(p,b)		BIT_SET(PORT ## p, b)
#define	PORT_TST(p,b)		BIT_TST(PORT ## p, b)
#define	PIN_TST(p,b)		BIT_TST(PIN  ## p, b)
#define	PIN_SET(p,b)		BIT_SET(PIN  ## p, b)

// Macros that can be used with an argument of the form (port,bit)
#define	INPUT(bit)		DDR_CLR bit
#define	OUTPUT(bit)		DDR_SET bit
#define	CLR(bit)		PORT_CLR bit
#define	SET(bit)		PORT_SET bit
#define	ISSET(bit)		PORT_TST bit
#define	TST(bit)		PIN_TST bit
#define	TOGGLE(bit)		PIN_SET bit

// Bit string macros
#define BIN8(n0)			\
  ((unsigned char)			\
   ( ((0x##n0##UL&0x00000001UL)>> 0)	\
    |((0x##n0##UL&0x00000010UL)>> 3)	\
    |((0x##n0##UL&0x00000100UL)>> 6)	\
    |((0x##n0##UL&0x00001000UL)>> 9)	\
    |((0x##n0##UL&0x00010000UL)>>12)	\
    |((0x##n0##UL&0x00100000UL)>>15)	\
    |((0x##n0##UL&0x01000000UL)>>18)	\
    |((0x##n0##UL&0x10000000UL)>>21)	\
   )					\
  )

#define BIN16(n1,n0)			\
  ((unsigned short)			\
   ( (((unsigned short)BIN8(n1))<<8)	\
    |(((unsigned short)BIN8(n0))<<0)	\
   )					\
  )

#define BIN32(n3,n2,n1,n0)		\
  ((unsigned long)			\
   ( (((unsigned long)BIN16(n3,n2))<<16)\
    |(((unsigned long)BIN16(n1,n0))<< 0)\
   )					\
  )