LPC1225 UART_init and interrupt problem

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by Efendi on Thu Jan 08 08:03:39 MST 2015
Hello ... I am using  the following code to UART1_init but during the simulation the DLL  and DLM registers don't keep its value in the end of code the DLL and DLM reset. Also I use __irq void UART1_IRQHandler(void) interrupt function but I can not get RX interrup to read the data.

void UART1_init(unsigned long baudrate)
// Var. Def.
uint32_t Fdiv;
NVIC_DisableIRQ(UART1_IRQn);   // Disable all UART1 intrruptes for initialize

// UART ports configuration.
LPC_IOCON->PIO0_8 &= ~0x07;    // UART1 I/O port2_12 config as UART1_RXD1
LPC_IOCON->PIO0_8 |= 0x03;     // UART1 RXD LOC0.

LPC_IOCON->PIO0_9 &= ~0x07;// UART1 I/O port1_13 config as UART1_TXD1
LPC_IOCON->PIO0_9 |= 0x03;     // UART1 TXD LOC0/.

    //Baudrate configuration.
    LPC_UART1->LCR = 0x83;                  //8 bits, no Parity, 1 Stop bit, and DLAB=1 enable it for config PCLK.
Fdiv = (((SystemCoreClock*LPC_SYSCON->SYSAHBCLKDIV)/LPC_SYSCON->UART0CLKDIV)/16)/baudrate;
    //Fdiv = ( UART1_PCLK / 16 ) / baudrate ;//baud rate.
LPC_UART1->DLM = Fdiv / 256;            // Config the baudrate register of UART1.         
    LPC_UART1->DLL = Fdiv % 256;

//Data packet configuration. 
LPC_UART1->LCR = 0x03;     // DLAB = 0, for config RS232.

// RS232 Multidrop Mode configuration
LPC_UART1->FCR = 0x07;     // Enable and reset TX and RX FIFO.
    NVIC_EnableIRQ(UART1_IRQn);      // Enable Nested Vector Interrupt Control (NVIC) of UART0.
    LPC_UART1->IER = 0x07;           // Enable RBR, THR and LSR