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C/C++ Users Group Library 1996 July
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C-C++ Users Group Library July 1996.iso
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v_08_12
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8n12035b
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1990-10-16
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745b
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24 lines
/* 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))