bf561 汇编指令集（二）

位操作指令 Bit Operations bitclr (r2, 3) ; /* clear bit 3 (the fourth bit from LSB) in R2 */ bitset (r2, 7) ; /* set bit 7 (the eighth bit from LSB) in R2 */ bittgl (r2, 24) ; /* toggle bit 24 (the 25th bit from LSB in R2 */ cc = bittst (r7, 15) ; /* test bit 15 TRUE in R7 */ cc = ! bittst (r3, 0) ; /* test bit 0 FALSE in R3 */ r7 = deposit (r4, r3) ; /* Special Applications：Video image overlay algorithms */ r7 = extract (r4, r3.l) (x) ; /*Special Applications Video image pattern recognition and separation algorithms */ bitmux (r2, r3, a0) (asr) ; /* right shift*/ bitmux (r3, r2, a0) (asl) ; /* left shift*/ r3.l = ones r7 ; /*loads the number of 1’s*/ /*Special Applications Software parity testing */ Shift/Rotate Operations Add with Shift p3 = (p3+p2)<<2 ; r3 = (r3+r2)<<1 ; Shift with Add p3 = p0+(p3<<1) ; Arithmetic Shift r0 >>>= 19 ; r3.l = r0.h << 12 (S) ; r3.l = r0.h >>> 7(s) ; r4 = ashift r2 by r7.l ; A1 = ashift A1 by r7.l ; Logical Shift p3 = p2 >> 1 ; r3.h = r0.h << 14 ; a0 = lshift a0 by r7.l ; ROT (Rotate) r4 = rot r1 by 8 ; a1 = rot a1 by -31 ; r4 = rot r1 by r2.l ;