

        /*          file mfp_macs.h          */

        /* M A C R O   D E F I N I T I O N S */

        /* cast operation for register references */
#define REGVAL(x)               (*(unsigned char *)(x))

        /* create bit mask for one bit on/off */
#define BITON_MASK(bitnum)      (1 << (bitnum))
#define BITOFF_MASK(bitnum)     (~(1 << (bitnum)))

        /* use given mask to set/clear bits in given byte */
#define SET_BITS(byte,mask)     REGVAL(byte) |= (mask)
#define CLR_BITS(byte,mask)     REGVAL(byte) &= (mask)

        /* set/clear given bit number in byte */
#define BIT_SET(byte,bitnum)    REGVAL(byte) |= (BITON_MASK(bitnum))
#define BIT_CLR(byte,bitnum)    REGVAL(byte) &= (BITOFF_MASK(bitnum))



