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用的是创龙的OMAP-L138的板子和XDS100v3仿真器,用的方法是TSCL = 0;
" Y4 }) V) [& B' M8 ` TSCH = 0;
7 X8 @& h7 Z( z2 h- i unsigned long long start,stop,overhead;
; H, g% |% ~+ L C8 U# N8 S start = _itoll(TSCH,TSCL);9 T8 O- R! ^. h" g8 W0 I
stop = _itoll(TSCH,TSCL); 5 l# |+ p1 N- \ A! j0 u% v0 R+ A* f/ N
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overhead = stop - start;
( A, X$ H" Q! [, gprintf("overhead run-time is %d\n",overhead);: n7 ]. n! }2 g3 I
/ ~" Z& v) o& ^3 G: s' f3 V2 wstart = _itoll(TSCH,TSCL);& _( L, z3 C0 m5 G9 s4 q! i; c4 o, A
//here is function/ Y7 X3 P* }* V% K1 K1 a: c
function();
* l3 j$ P9 Y$ ^stop = _itoll(TSCH,TSCL);3 `9 R& D; S7 d2 f$ P! }
printf("The function run-time time is %lu\n",(stop - start - overhead));
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为什么每次测量出来的时间都不一致?测量出来的不是一个固定的值。5 i% Q8 ]2 U) B. b) i" N
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