Hello again,
Please be sure that your bus clock is at 60 MHz. The code below sets the bus clock at this frequency (it was generated by PEx).
void init_hardware()
{
/* Disable the WDOG module */
/* WDOG_UNLOCK: WDOGUNLOCK=0xC520 */
WDOG_UNLOCK = WDOG_UNLOCK_WDOGUNLOCK(0xC520); /* Key 1 */
/* WDOG_UNLOCK: WDOGUNLOCK=0xD928 */
WDOG_UNLOCK = WDOG_UNLOCK_WDOGUNLOCK(0xD928); /* Key 2 */
/* WDOG_STCTRLH: ??=0,DISTESTWDOG=0,BYTESEL=0,TESTSEL=0,TESTWDOG=0,??=0,??=1,WAITEN=1,STOPEN=1,DBGEN=0,ALLOWUPDATE=1,WINEN=0,IRQRSTEN=0,CLKsrc=1,WDOGEN=0 */
WDOG_STCTRLH = WDOG_STCTRLH_BYTESEL(0x00) |
WDOG_STCTRLH_WAITEN_MASK |
WDOG_STCTRLH_STOPEN_MASK |
WDOG_STCTRLH_ALLOWUPDATE_MASK |
WDOG_STCTRLH_CLKSRC_MASK |
0x0100U;
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=3,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x03) |
SIM_CLKDIV1_OUTDIV4(0x03); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
if ((PMC_REGSC & PMC_REGSC_ACKISO_MASK) != 0x0U)
{
/* PMC_REGSC: ACKISO=1 */
PMC_REGSC |= PMC_REGSC_ACKISO_MASK; /* Release IO pads after wakeup from VLLS mode. */
}
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=0,OUTDIV3=1,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x00) |
SIM_CLKDIV1_OUTDIV3(0x01) |
SIM_CLKDIV1_OUTDIV4(0x03); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=0 */
SIM_SOPT2 &= (uint32_t)~(uint32_t)(SIM_SOPT2_PLLFLLSEL_MASK); /* Select FLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=3 */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03); /* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
/* Switch to FEI Mode */
/* MCG_C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = MCG_C1_CLKS(0x00) |
MCG_C1_FRDIV(0x00) |
MCG_C1_IREFS_MASK |
MCG_C1_IRCLKEN_MASK;
/* MCG_C2: LOCRE0=0,??=0,RANGE0=0,HGO0=0,EREFS0=0,LP=0,IRCS=0 */
MCG_C2 = MCG_C2_RANGE0(0x00);
/* MCG_C4: DMX32=0,DRST_DRS=2 */
MCG_C4 = (uint8_t)((MCG_C4 & (uint8_t)~(uint8_t)(
MCG_C4_DMX32_MASK |
MCG_C4_DRST_DRS(0x01)
)) | (uint8_t)(
MCG_C4_DRST_DRS(0x02)
));
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
MCG_C5 = MCG_C5_PRDIV0(0x00);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) == 0x00U); /* Check that the source of the FLL reference clock is the internal reference clock. */
while((MCG_S & 0x0CU) != 0x00U); /* Wait until output of the FLL is selected */
}
Also, I wrote the code below which initializes the UART5 for the K21 MCU with interrupts.
static uint8_t* dataToSend;
static uint8_t* dataToReceive;
static uint8_t amountOfBytesToSend;
void UART5_Init()
{
//Enabled the clock gate for UART5.
SIM_SCGC1 |= SIM_SCGC1_UART5_MASK;
//Enabled the clock gate for port D.
SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK;
// PORTD_PCR8: ISF=0,MUX=3.
PORTD_PCR8 = ((PORTD_PCR8 & ~(PORT_PCR_ISF_MASK | PORT_PCR_MUX_MASK)) | PORT_PCR_MUX(0x03));
// PORTD_PCR9: ISF=0,MUX=3.
PORTD_PCR9 = ((PORTD_PCR9 & ~(PORT_PCR_ISF_MASK | PORT_PCR_MUX_MASK)) | PORT_PCR_MUX(0x03));
//Disable the TE and RE register.
UART_C2_REG(UART5_BASE_PTR) &= ~(UART_C2_TE_MASK | UART_C2_RE_MASK);
//Clear the C1 register.
UART_C1_REG(UART5_BASE_PTR) = 0;
// Calculate baud settings.
uint32_t sysclk = 60000000; //Bus clock.
uint32_t baud = 115200; //Baudrate.
uint32_t sbr = sysclk / (baud * 16);
// Save off the current value of the UART5_BDH except for the SBR field.
uint32_t temp = UART_BDH_REG(UART5_BASE_PTR) & ~(UART_BDH_SBR(0x1F));
UART_BDH_REG(UART5_BASE_PTR) = temp | UART_BDH_SBR(((sbr & 0x1F00) >> 8));
UART_BDL_REG(UART5_BASE_PTR) = (uint8_t)(sbr & UART_BDL_SBR_MASK);
// Determine if a fractional divider is needed to get closer to the baud rate.
uint32_t brfa = (((sysclk*32000)/(baud * 16)) - (sbr * 32));
// Save off the current value of the UARTx_C4 register except for the BRFA field.
temp = UART_C4_REG(UART5_BASE_PTR) & ~(UART_C4_BRFA(0x1F));
UART_C4_REG(UART5_BASE_PTR) = temp | UART_C4_BRFA(brfa);
// Enable the receiver, the transmitter and the interrupts.
UART_C2_REG(UART5_BASE_PTR) |= (/*UART_C2_TCIE_MASK | UART_C2_RIE_MASK |*/ UART_C2_TE_MASK | UART_C2_RE_MASK);
//Enable the interrupts.
NVIC_ICPR(INT_UART5_RX_TX / 32) = (1 << ((INT_UART5_RX_TX - 16) % 32)); //Clear all the pending events
NVIC_ISER(INT_UART5_RX_TX / 32) = (1 << ((INT_UART5_RX_TX - 16) % 32)); //Enables External Interrupt for UART0
}
void UART5_Send(uint8_t* data, uint8_t bytesAmount)
{
amountOfBytesToSend = bytesAmount;
dataToSend = data;
UART5_D = *dataToSend;
UART5_C2 |= UART_C2_TCIE_MASK; //Enable interrupt when the transmission is completed.
}
void UART5_Receive(uint8_t* data)
{
dataToReceive = data;
UART5_C2 |= UART_C2_RIE_MASK; //Enable interrupt when data has been received.
}
void UART5_Status_IRQHandler()
{
if (UART5_S1 & UART_S1_RDRF_MASK) //If the interrupt is caused by a reception.
{
*dataToReceive++ = UART5_D; //Read the data.
}
else if (UART5_S1 & UART_S1_TC_MASK) //If the interrupt is caused by a transmission.
{
if(amountOfBytesToSend--) //If there is data to send, send more data.
{
UART5_D = *dataToSend++;
}
else
{
UART5_C2 &= ~UART_C2_TCIE_MASK;
}
}
}
In CodeWarrior the UART5 ISR is not enabled by default for this MCU, to enable it you have to follow the next steps:
1. Open the archive "Project_Settings/Startup_Code/kinetis_sysinit.c"
2. In the functions array the fields 84 and 85 are 0's, you need to replace it for the functions:
UART5_Status_IRQHandler
UART5_ERR_IRQHandler
3. Declare the function prototype by copying the next two lines in this archive.
void UART5_Status_IRQHandler() __attribute__ ((weak, alias("Default_Handler")));
void UART5_ERR_IRQHandler() __attribute__ ((weak, alias("Default_Handler")));
I hope this helps. I remain at your service.
Regards,
Earl Orlando Ramírez-Sánchez.
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