Problem mit UART auf Stellaris TM4C123GH6PGE = LM4F232H5QD

[Fabian Eichner (Gast)]

Hallo Leute!

Habe im Rahmen eines Projektes Probleme mit dem Cortex M4 TM4C123GH6PGE, 
bzw. dessen UART (UART4):

 const int idelay = 1000;        //for delay

 unsigned long int* RCGCUART;    //address of Rcgcuart
 unsigned long int* RCGCGPIO;    //..
 unsigned long int* GPIOAFSEL;   //..
 unsigned long int* GPIOPCTL;    //..
 unsigned long int* UARTCTL;     //..
 unsigned long int* UARTIBRD;    //..
 unsigned long int* UARTFBRD;    //..
 unsigned long int* UARTLCRH;    //..
 unsigned long int* PPUART;      //..

//1.Enable UART via RCGCUART Register page 333
//Base address 0x400F.E000 is a System Control Register as seen on page 97
//Offset address 0x618 Adress for the RCGCUART Register
//Addition gives the adresse: 0x400F.E618
//to set the UART4 the fifth Bit must be set.
RCGCUART = 0x400FE618;
//*RCGCUART &= 0xEF; // Disable UART4
*RCGCUART |= 0x10; //Enable UART4
delay_ms(idelay);

//2.Enable the clock to the appropiate GPIO module via RCGCGPIO page 328
//The Base address is 0x400F.E000
//The offset address is 0x608
//That gives: 0x400F.E608
//PORTC is the third Bit so : 0x4 = 0b100
RCGCGPIO = 0x400FE608;
*RCGCGPIO |= 0x4;
delay_ms(idelay);

//3.Setting the GPIO AFSEL for the appropiate PINs
//GPIO PORTC APB Base is on 0x4000.6000
//Offset is 0x420 -> that gives in total 0x4000.6420
//PORTC4/5 Uart4 is on Pin 36/35
GPIOAFSEL = 0x40006420;
*GPIOAFSEL |= 0x30;
delay_ms(idelay);

//4.Configure Current level and slew rate control
//2mA default
//Slew rate default no slew rate control

//5.Configure PMCn fields in the GPIOPCTL register to asign the UART Signals to the appropiate pin
//Base of the GPIOPCTL register is 0x4000.6000 for PORTC APB
//The offset is 0x52C
//That gives 0x4000652C
//Write the appropiate value for UART4 into the Pin4 and Pin5 fields. Should be 0x2;
GPIOPCTL = 0x4000652C;
*GPIOPCTL |= 0x00110000;
delay_ms(idelay);

//Configuration of the UART:
//1.Disable UART
//Disabling by resetting UARTEN in the UARTCTL register
//Base address is 0x4001.0000
//The offset address is 0x030
//UARTEN is the first Bit
UARTCTL = 0x40010030;
*UARTCTL &= 0xFFFFFFFE;
*UARTCTL |= 0x300;
delay_ms(idelay);
  
//2.BAUDRATE
//BRD = 16000000 / (16 * 115200) = 8,6805°
//UARTFBRD = integer(0,6805 * 64 + 0.5) = 44
//UARTIBRD base is on 0x4001.0000
//and offset is 0x024
//UARTFBRD base is on 0x4001.0000
//and offset is 0x028
UARTIBRD = 0x40010024;
*UARTIBRD |= 0x8;
UARTFBRD = 0x40010028;
*UARTFBRD |= 0x2C;
delay_ms(idelay);
  
//3.data length, parity and stop bit
//This is set in the UARTLCRH register
//The base address is 0x4001.0000
//The offset address is 0x02C
// Bit 5 and 6 are the data length. 0x3 is 8 bits.
// no parity and 1 stop bit default
UARTLCRH = 0x4001002C;
*UARTLCRH |= 0x60; //0b01100000
delay_ms(idelay);
  
//4.Enable the UART4 again
UARTCTL = 0x40010030;
*UARTCTL |= 0x00000001;
delay_ms(idelay);

//Transmit on UARTDR register
//Base address for UART4 0x4001.0000
//offset address is 0x00
unsigned long int* UARTDR = 0x40010000;
*UARTDR |= 0x41;                             //Letter A

Das ist mein Code, hoffentlich leserlich! Verzweifle wirklich, schon 
alles probiert!
Das Problem ist, dass zwar Idle anliegt (Leitung auf High) (mit Oszi 
gemessen), aber kein Sendevorgang stattfindet.

Hoffe um eure Hilfe!

MfG Fabian