Posted on October 15, 2015 at 00:00
clive1 you are correct regarding TIM3.
Overview: I have two external inputs. The one is the clock for TIM3 which I am using as a counter. The other input resets TIM3. Compare reg1 on TIM 3 triggers an interrupt, the interrupt enables the slave mode of TIM4 which is being clocked by the system clock. When the count reaches the TIM4 compare 1 value I want it to trigger the DMA. In the debugger I can see that TIM4 is counting up. The DMA registers all stay unchanged and the interrupt at the end of the DMA output is not triggered. Sorry about the pastes but program is made up of multiple modules, but here are most of the settings Prescaler value: PrescalerValue = (uint16_t) (SystemCoreClock / 8000000) - 1; The system clock is 72Mhz The compare values are: TIM4X_OFFSETuint16_t PrescalerValue = 0;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);//GPIOB clock enable
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);//GPIOC clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //TIM3 clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); //TIM4 clock enable
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);//DMA1 clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);//SPI2 clock enable
//GPIO Setup - input
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5 ; // we want to configure AF pins on port B
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; // we want the pins to be alternate functions
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; // this sets the GPIO modules clock speed
GPIO_InitStruct.GPIO_OType = GPIO_OType_OD; // this sets the pin type to push / pull (as opposed to open drain)
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; // this sets the pullup / pulldown resistors
GPIO_Init(GPIOB, &GPIO_InitStruct);
//GPIO Setup - input
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6; // we want to configure AF pins on port C
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; // we want the pins to be alternate functions
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; // this sets the GPIO modules clock speed
GPIO_InitStruct.GPIO_OType = GPIO_OType_OD; // this sets the pin type to opposed to open drain
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; // this sets the pullup / pulldown resistors
GPIO_Init(GPIOC, &GPIO_InitStruct);
//GPIO Setup - output
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_15 ; // we want to configure AF pins on port B
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; // we want the pins to be alternate functions
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; // this sets the GPIO modules clock speed
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; // this sets the pin type to push / pull (as opposed to open drain)
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP; // this sets the pullup / pulldown resistors
GPIO_Init(GPIOB, &GPIO_InitStruct);
//-----------------------------------------------------------------
/* Connect inputs to alternate function 2 - AF2 */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_2);//ch2 on Tim3
GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_2);//ch1 on Tim3
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_5); //MOSI on SPI2// Enable the TIM3 gloabal Interrupt
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
//Enable DMA1 channel IRQ Channel
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
void DMA1_Channel1_IRQHandler(void)
{
DMA_ClearITPendingBit( DMA1_IT_TC1);
DMA_InitStructure.DMA_MemoryBaseAddr += COL_COUNT_MAX;
DMA_Init(DMA1_Channel1, &DMA_InitStructure);//send values to DMA registers
LineCnt++;
}void TIM3_IRQHandler(void)
{
if(TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET)//int caused by compare1
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
if(MustStart)
{
TIM_SelectSlaveMode(TIM4, TIM_SlaveMode_Combined_ResetTrigger);//enable TIM4 trigger mode
MustStart = 0;
TIM_OCInitStructure.TIM_Pulse = END1;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
LineCnt = 0;
GrafRow = 0;
}
else
{
TIM_SelectSlaveMode(TIM4, 0);//disable TIM4 trigger mode
MustStart = 1;
TIM_OCInitStructure.TIM_Pulse = START1;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
}
}
/*if(TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)//int caused by TIM3 update
{
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
}*/
}TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);// Time Base configuration
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 0xffff;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
//setup the output compare
TIM_OCStructInit(&TIM_OCInitStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_Pulse = START1;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0);//set xternal clk source to TI2 which comes from AF2 port B.5
TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Combined_ResetTrigger);//this should cause a reset and update
TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1);//select TI1 as reset input - comes from ch1
TIM_ITConfig(TIM3, /*TIM_IT_Update | */TIM_IT_CC1, ENABLE);//this should trigger interrupt when TIM3 {gets reset or} when compare1 matches
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);//??
TIM_ARRPreloadConfig(TIM3, DISABLE); //??
//Select the Master Slave Mode
TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable);
TIM_SelectOutputTrigger(TIM3, TIM_TRGOSource_Update);
TIM_Cmd(TIM3, ENABLE);