void main(void) {
rccInit();
timerInit();
configInit();
adcInit();
fetInit();
serialInit();
runInit();
cliInit();
owInit();
runDisarm(REASON_STARTUP);
inputMode = ESC_INPUT_PWM;
fetSetDutyCycle(0);
fetBeep(200, 100);
fetBeep(300, 100);
fetBeep(400, 100);
fetBeep(500, 100);
fetBeep(400, 100);
fetBeep(300, 100);
fetBeep(200, 100);
pwmInit();
statusLed = digitalInit(GPIO_STATUS_LED_PORT, GPIO_STATUS_LED_PIN);
digitalHi(statusLed);
errorLed = digitalInit(GPIO_ERROR_LED_PORT, GPIO_ERROR_LED_PIN);
digitalHi(errorLed);
#ifdef ESC_DEBUG
tp = digitalInit(GPIO_TP_PORT, GPIO_TP_PIN);
digitalLo(tp);
#endif
// self calibrating idle timer loop
{
volatile unsigned long cycles;
volatile unsigned int *DWT_CYCCNT = (int *)0xE0001004;
volatile unsigned int *DWT_CONTROL = (int *)0xE0001000;
volatile unsigned int *SCB_DEMCR = (int *)0xE000EDFC;
*SCB_DEMCR = *SCB_DEMCR | 0x01000000;
*DWT_CONTROL = *DWT_CONTROL | 1; // enable the counter
minCycles = 0xffff;
while (1) {
idleCounter++;
NOPS_4;
cycles = *DWT_CYCCNT;
*DWT_CYCCNT = 0; // reset the counter
// record shortest number of instructions for loop
totalCycles += cycles;
if (cycles < minCycles)
minCycles = cycles;
}
}
}
void rccConfiguration(void) {
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOB | RCC_AHB1Periph_GPIOC | RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOE |
RCC_AHB1Periph_GPIOF | RCC_AHB1Periph_GPIOG | RCC_AHB1Periph_GPIOH,
ENABLE);
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_Init(GPIOE, &GPIO_InitStructure);
// exclude PA13 & PA14 for SWD
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All & ~(GPIO_Pin_13 | GPIO_Pin_14);
GPIO_Init(GPIOA, &GPIO_InitStructure);
#ifdef RCC_EN1_PORT
en1 = digitalInit(RCC_EN1_PORT, RCC_EN1_PIN, 1);
#endif
#ifdef RCC_EN2_PORT
en2 = digitalInit(RCC_EN2_PORT, RCC_EN2_PIN, 0);
#endif
#ifdef RCC_SYSOFF_PORT
sysoff = digitalInit(RCC_SYSOFF_PORT, RCC_SYSOFF_PIN, 0);
#endif
#ifdef RCC_STEPUP_EN_PORT
stepupEn = digitalInit(RCC_STEPUP_EN_PORT, RCC_STEPUP_EN_PIN, 1);
#endif
#ifdef RCC_SYNC_PORT
sync = digitalInit(RCC_SYNC_PORT, RCC_SYNC_PIN, 1);
#endif
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1 | RCC_AHB1Periph_DMA2, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
// enable timer clocks
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3 | RCC_APB1Periph_TIM4 | RCC_APB1Periph_TIM7, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_TIM8 | RCC_APB2Periph_TIM9 | RCC_APB2Periph_TIM10 | RCC_APB2Periph_TIM11,
ENABLE);
SYSCFG_CompensationCellCmd(ENABLE);
// Clear reset flags
RCC_ClearFlag();
RCC_GetClocksFreq(&rccClocks);
pwmZeroTimers();
}
static void radioRCSelect(uint8_t rcPort, uint8_t level) {
#ifdef RADIO_RC1_SELECT_PORT
if (rcPort == 0)
radioData.select[0] = digitalInit(RADIO_RC1_SELECT_PORT, RADIO_RC1_SELECT_PIN, level);
#endif
#ifdef RADIO_RC2_SELECT_PORT
if (rcPort == 1)
radioData.select[1] = digitalInit(RADIO_RC2_SELECT_PORT, RADIO_RC2_SELECT_PIN, level);
#endif
}
void supervisorInit(void) {
memset((void *)&supervisorData, 0, sizeof(supervisorData));
supervisorData.readyLed = digitalInit(SUPERVISOR_READY_PORT, SUPERVISOR_READY_PIN, 0);
#ifdef SUPERVISOR_DEBUG_PORT
supervisorData.debugLed = digitalInit(SUPERVISOR_DEBUG_PORT, SUPERVISOR_DEBUG_PIN, 0);
#endif
supervisorData.gpsLed = digitalInit(GPS_LED_PORT, GPS_LED_PIN, 0);
supervisorData.state = STATE_INITIALIZING;
supervisorTaskStack = aqStackInit(SUPERVISOR_STACK_SIZE, "SUPERVISOR");
supervisorData.supervisorTask = CoCreateTask(supervisorTaskCode, (void *)0, SUPERVISOR_PRIORITY, &supervisorTaskStack[SUPERVISOR_STACK_SIZE-1], SUPERVISOR_STACK_SIZE);
}
spiClient_t *spiClientInit(SPI_TypeDef *spi, uint16_t baud, GPIO_TypeDef *csPort, uint16_t csPin, volatile uint32_t *flag, spiCallback_t *callback) {
spiClient_t *client;
client = (spiClient_t *)aqCalloc(1, sizeof(spiClient_t));
#ifdef SPI_SPI1_CLOCK
if (spi == SPI1) {
client->interface = 0;
spi1Init();
}
#endif
#ifdef SPI_SPI2_CLOCK
if (spi == SPI2) {
client->interface = 1;
spi2Init();
}
#endif
#ifdef SPI_SPI3_CLOCK
if (spi == SPI3) {
client->interface = 2;
spi3Init();
}
#endif
client->cs = digitalInit(csPort, csPin, 1);
spiDeselect(client);
spiChangeBaud(client, baud);
client->flag = flag;
client->callback = callback;
return client;
}
void rccBootLoader(void) {
// check for magic cookie
if (rccReadBkpDr() == 0xDECEA5ED) {
digitalPin *statusLed, *errorLed;
rccWriteBkpDr(0); // reset flag
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
statusLed = digitalInit(GPIO_STATUS_LED_PORT, GPIO_STATUS_LED_PIN);
digitalLo(statusLed);
errorLed = digitalInit(GPIO_ERROR_LED_PORT, GPIO_ERROR_LED_PIN);
digitalLo(errorLed);
// jump to boot loader ROM
__asm volatile ("LDR R0, =0x1FFFF000\n"
"LDR SP,[R0, #0]\n"
"LDR R0,[R0, #4]\n"
"BX R0\n");
}
void adcInit(void) {
GPIO_InitTypeDef GPIO_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
AQ_NOTICE("ADC init\n");
memset((void *)&adcData, 0, sizeof(adcData));
// energize mag's set/reset circuit
adcData.magSetReset = digitalInit(GPIOE, GPIO_Pin_10, 1);
// use auto-zero function of gyros
adcData.rateAutoZero = digitalInit(GPIOE, GPIO_Pin_8, 0);
// bring ACC's SELF TEST line low
adcData.accST = digitalInit(GPIOE, GPIO_Pin_12, 0);
// bring ACC's SCALE line low (ADXL3X5 requires this line be tied to GND or left floating)
adcData.accScale = digitalInit(GPIOC, GPIO_Pin_15, 0);
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5;
GPIO_Init(GPIOC, &GPIO_InitStructure);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 | RCC_APB2Periph_ADC3, ENABLE);
adcData.sample = ADC_SAMPLES - 1;
// Use STM32F4's Triple Regular Simultaneous Mode capable of ~ 6M samples per second
DMA_DeInit(ADC_DMA_STREAM);
DMA_InitStructure.DMA_Channel = ADC_DMA_CHANNEL;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)adcDMAData.adc123Raw1;
DMA_InitStructure.DMA_PeripheralBaseAddr = ((uint32_t)0x40012308);
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = ADC_CHANNELS * 3 * 2;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(ADC_DMA_STREAM, &DMA_InitStructure);
DMA_ITConfig(ADC_DMA_STREAM, DMA_IT_HT | DMA_IT_TC, ENABLE);
DMA_ClearITPendingBit(ADC_DMA_STREAM, ADC_DMA_FLAGS);
DMA_Cmd(ADC_DMA_STREAM, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = ADC_DMA_IRQ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// ADC Common Init
ADC_CommonStructInit(&ADC_CommonInitStructure);
ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_RegSimult;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_CommonInit(&ADC_CommonInitStructure);
// ADC1 configuration
ADC_StructInit(&ADC_InitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 16;
ADC_Init(ADC1, &ADC_InitStructure);
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGX, 1, ADC_SAMPLE_TIME); // magX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGX, 2, ADC_SAMPLE_TIME); // magX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGX, 3, ADC_SAMPLE_TIME); // magX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGX, 4, ADC_SAMPLE_TIME); // magX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGY, 5, ADC_SAMPLE_TIME); // magY
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGY, 6, ADC_SAMPLE_TIME); // magY
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGY, 7, ADC_SAMPLE_TIME); // magY
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGY, 8, ADC_SAMPLE_TIME); // magY
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGZ, 9, ADC_SAMPLE_TIME); // magZ
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGZ, 10, ADC_SAMPLE_TIME); // magZ
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGZ, 11, ADC_SAMPLE_TIME); // magZ
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_MAGZ, 12, ADC_SAMPLE_TIME); // magZ
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_RATEX, 13, ADC_SAMPLE_TIME); // rateX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_RATEX, 14, ADC_SAMPLE_TIME); // rateX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_RATEX, 15, ADC_SAMPLE_TIME); // rateX
ADC_RegularChannelConfig(ADC1, ADC_CHANNEL_RATEX, 16, ADC_SAMPLE_TIME); // rateX
// Enable ADC1 DMA since ADC1 is the Master
ADC_DMACmd(ADC1, ENABLE);
// ADC2 configuration
ADC_StructInit(&ADC_InitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 16;
ADC_Init(ADC2, &ADC_InitStructure);
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_RATEY, 1, ADC_SAMPLE_TIME); // rateY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_RATEY, 2, ADC_SAMPLE_TIME); // rateY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_RATEY, 3, ADC_SAMPLE_TIME); // rateY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_RATEY, 4, ADC_SAMPLE_TIME); // rateY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCX, 5, ADC_SAMPLE_TIME); // accX
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCX, 6, ADC_SAMPLE_TIME); // accX
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCX, 7, ADC_SAMPLE_TIME); // accX
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCX, 8, ADC_SAMPLE_TIME); // accX
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCY, 9, ADC_SAMPLE_TIME); // accY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCY, 10, ADC_SAMPLE_TIME); // accY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCY, 11, ADC_SAMPLE_TIME); // accY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCY, 12, ADC_SAMPLE_TIME); // accY
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCZ, 13, ADC_SAMPLE_TIME); // accZ
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCZ, 14, ADC_SAMPLE_TIME); // accZ
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCZ, 15, ADC_SAMPLE_TIME); // accZ
ADC_RegularChannelConfig(ADC2, ADC_CHANNEL_ACCZ, 16, ADC_SAMPLE_TIME); // accZ
// ADC3 configuration
ADC_StructInit(&ADC_InitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 16;
ADC_Init(ADC3, &ADC_InitStructure);
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_RATEZ, 1, ADC_SAMPLE_TIME); // rateZ
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_RATEZ, 2, ADC_SAMPLE_TIME); // rateZ
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_RATEZ, 3, ADC_SAMPLE_TIME); // rateZ
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_RATEZ, 4, ADC_SAMPLE_TIME); // rateZ
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_TEMP1, 5, ADC_SAMPLE_TIME); // temp1
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_TEMP2, 6, ADC_SAMPLE_TIME); // temp2
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES1, 7, ADC_SAMPLE_TIME); // pressure1
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES1, 8, ADC_SAMPLE_TIME); // pressure1
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES1, 9, ADC_SAMPLE_TIME); // pressure1
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES1, 10, ADC_SAMPLE_TIME); // pressure1
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_VIN, 11, ADC_SAMPLE_TIME); // Vin
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_TEMP3, 12, ADC_SAMPLE_TIME); // temp3
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES2, 13, ADC_SAMPLE_TIME); // pressure2
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES2, 14, ADC_SAMPLE_TIME); // pressure2
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES2, 15, ADC_SAMPLE_TIME); // pressure2
ADC_RegularChannelConfig(ADC3, ADC_CHANNEL_PRES2, 16, ADC_SAMPLE_TIME); // pressure2
// Enable DMA request after last transfer (Multi-ADC mode)
ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE);
// Enable
ADC_Cmd(ADC1, ENABLE);
ADC_Cmd(ADC2, ENABLE);
ADC_Cmd(ADC3, ENABLE);
adcData.adcFlag = CoCreateFlag(1, 0);
adcTaskStack = aqStackInit(ADC_STACK_SIZE, "ADC");
adcData.adcTask = CoCreateTask(adcTaskCode, (void *)0, ADC_PRIORITY, &adcTaskStack[ADC_STACK_SIZE-1], ADC_STACK_SIZE);
// Start ADC1 Software Conversion
ADC_SoftwareStartConv(ADC1);
yield(100);
// set initial temperatures
adcData.temp1 = adcIDGVoltsToTemp(adcData.voltages[ADC_VOLTS_TEMP1]);
adcData.temp2 = adcIDGVoltsToTemp(adcData.voltages[ADC_VOLTS_TEMP2]);
adcData.temp3 = adcT1VoltsToTemp(adcData.voltages[ADC_VOLTS_TEMP3]);
analogData.vIn = adcVsenseToVin(adcData.voltages[ADC_VOLTS_VIN]);
adcCalibOffsets();
}
void main(void) {
rccInit();
statusLed = digitalInit(GPIO_STATUS_LED_PORT, GPIO_STATUS_LED_PIN);
errorLed = digitalInit(GPIO_ERROR_LED_PORT, GPIO_ERROR_LED_PIN);
#ifdef ESC_DEBUG
tp = digitalInit(GPIO_TP_PORT, GPIO_TP_PIN);
digitalLo(tp);
#endif
timerInit();
configInit();
adcInit();
fetInit();
serialInit();
canInit();
runInit();
cliInit();
owInit();
runDisarm(REASON_STARTUP);
inputMode = ESC_INPUT_PWM;
fetSetDutyCycle(0);
fetBeep(200, 100);
fetBeep(300, 100);
fetBeep(400, 100);
fetBeep(500, 100);
fetBeep(400, 100);
fetBeep(300, 100);
fetBeep(200, 100);
pwmInit();
digitalHi(statusLed);
digitalHi(errorLed);
// self calibrating idle timer loop
{
uint32_t lastRunCount;
uint32_t thisCycles, lastCycles;
volatile uint32_t cycles;
volatile uint32_t *DWT_CYCCNT = (uint32_t *)0xE0001004;
volatile uint32_t *DWT_CONTROL = (uint32_t *)0xE0001000;
volatile uint32_t *SCB_DEMCR = (uint32_t *)0xE000EDFC;
*SCB_DEMCR = *SCB_DEMCR | 0x01000000;
*DWT_CONTROL = *DWT_CONTROL | 1; // enable the counter
minCycles = 0xffff;
while (1) {
idleCounter++;
if (runCount != lastRunCount && !(runCount % (RUN_FREQ / 1000))) {
if (commandMode == CLI_MODE)
cliCheck();
else
binaryCheck();
lastRunCount = runCount;
}
thisCycles = *DWT_CYCCNT;
cycles = thisCycles - lastCycles;
lastCycles = thisCycles;
// record shortest number of instructions for loop
totalCycles += cycles;
if (cycles < minCycles)
minCycles = cycles;
}
}
}