NXP的LPC175x/6x系列超频

tyou

除了x9本身就是120M max，其他系列超频120M应该没有问题吧？
能测试的兄弟们搞一下？


The EEMBC certification lab has tested the microcontroller at 72,100, and 120 MHz (overclocked?), the performance and efficiency put down as a consequence of the memory architecture of the microcontroller.


或者想问问为什么x9是120M，而其他是100M，具体原因是？

tyou

刚到了1768的小板，第一个任务就是超频，自己来做！

测试结果：
CCLK         FLASHCFG             IAR Performance(Loops/sec)
141.12MHz         6 clocks                 8454
141.12Mhz         5 clocks                 8466
72Mhz         5 clocks                 4311
72Mhz         4 clocks                 4318


结果发现FLASH等待周期数似乎影响不大?
确认 测试代码段在FLASH里： _CalcPrimes             0x0000076d   0x5c  Code  Lc  OS_PerformanceTest.o [1]


TEST METHOD:
File    : OS_PerformanceTest.c (medium optimize)
Purpose : Performance test program
          It checks the performance of the entire system, outputing one
          result value per second. Higher values are better.
          The program computes the first 1000 prime numbers in a loop.
          The value output is the number of times this could be performed
          in a second.
          Version 2.0, July-14 2008
----------------------------------------------------------------------
Reference values -  RAM configuration:
ARM926-EJS fully chached, 201.0MHz, IAR EWARM V5.20, Thumb Mode => 11834 Loops/sec => 58.9 Loops/sec/MHz
ARM926-EJS fully chached, 201.0MHz, IAR EWARM V5.20, ARM   Mode => 12497 Loops/sec => 62.2 Loops/sec/MHz
ARM7-TDMI                  47.9MHz, IAR EWARM V5.20, Thumb Mode =>  2656 Loops/sec => 55.4 Loops/sec/MHz
ARM7-TDMI                  47.9MHz, IAR EWARM V5.20, ARM   Mode =>  2646 Loops/sec => 55.2 Loops/sec/MHz

tyou

和电脑比较一下
E4300 @2.4G DDR2@333MHz(VC6,Release)  ~= 258700

tyou

测试代码：

char aIsPrime[1000];
int NumPrimes;

/*********************************************************************
*
*       _CalcPrimes
*/
static void _CalcPrimes(int NumItems) {
  int i;
  //
  // Mark all as potential prime numbers
  //
  memset(aIsPrime, 1, NumItems);
  //
  // 2 deserves a special treatment
  //
  for (i = 4; i < NumItems; i += 2) {
    aIsPrime = 0;     // Cross it out: not a prime
  }
  //
  // Cross out multiples of every prime starting at 3. Crossing out starts at i^2.
  //
  for (i = 3; i * i < NumItems; i++) {
    if (aIsPrime) {
      int j;

      j = i * i;    // The square of this prime is the first we need to cross out
      do {
        aIsPrime[j] = 0;     // Cross it out: not a prime
        j += 2 * i;          // Skip even multiples (only 3*, 5*, 7* etc)
      } while (j < NumItems);
    }
  }
  //
  // Count prime numbers
  //
  NumPrimes = 0;
  for (i = 2; i < NumItems; i++) {
    if (aIsPrime) {
      NumPrimes++;
    }
  }
}

/*********************************************************************
*
*       _PrintDec
*/
static void _PrintDec(unsigned v) {
  int Digit;
  int r;

  Digit = 10;
  while (Digit < v) {
    Digit *= 10;
  }
  do {
    Digit /= 10;
    r = v / Digit;
    v -= r * Digit;
    putchar(r + '0');
  } while (v | (Digit > 1));
}

/*********************************************************************
*
*       _PrintResult
*/
static void _PrintResult(unsigned Cnt) {
  if (NumPrimes != 168) {
    puts("Error");
  } else {
    puts("Loops/sec:");
    _PrintDec(Cnt);
  }
  puts("\n");
}

/*********************************************************************
*
*       HPTask
*/
static void HPTask(void) {
  int Cnt;
  __int64 TestTime;

  cout << timeGetTime() << endl;
  Sleep(1000);  
  cout << timeGetTime() << endl;

  while(1) {
    Cnt = 0;
    TestTime = timeGetTime() + 1000;
    while ((TestTime - timeGetTime()) >= 0) {
      _CalcPrimes(sizeof(aIsPrime));
      Cnt++;
    }
    _PrintResult(Cnt);
  }
}

Excellence

为什么要超频？仅仅是好玩？
还是打算做产品？

bluelucky

tyou一定是爱好者。
虽然超频不能做产品，但我估计随着制程从180nm往90nm走，提前感受一下也挺好的啊