CC3200 DMA UART Ping-Pong mode setup

Hello!

I am trying to set up the DMA with UARTA1 in Ping-Pong mode. So far i didn't succeed in getting the whole thing working. 

When i run the code the UART Interrupt Handler gets called. However my code breaks up after reaching the Ping-Pong setup the seccond time.

My occiloscope shows a constant 3.3 V level as outPut of my UART. 

Here is my code ... 

static void UARTIntHandler_1()
{
	Message("\r\n [+] UARTIntHandler_1 ...");
    if(!bTxDone_1)
    {
        MAP_UARTDMADisable(UARTA1_BASE,UART_DMA_TX);
        bTxDone_1 = true;
    }

    MAP_UARTIntClear(UARTA1_BASE,UART_INT_DMATX);
}

void main()
{

    BoardInit();
    bTxDone_1 = false;


    int i=0;
    unsigned char logicOne = 0xf8;

	//for (i=0 ;i < 384; i++) {
    while(i<384){
		LEDBuffer[i] = logicOne;
		i++;
	}
    PinMuxConfig();
    UDMAInit();

    MAP_UARTIntRegister(UARTA1_BASE,UARTIntHandler_1); // LED
    MAP_UARTIntEnable(UARTA1_BASE,UART_INT_DMATX); // LED

    MAP_UARTConfigSetExpClk(CONSOLE,MAP_PRCMPeripheralClockGet(CONSOLE_PERIPH),
                            UART_BAUD_RATE,
                            (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
                            UART_CONFIG_PAR_NONE));

    InitTerm();
    ClearTerm();
    DisplayBanner(APP_NAME);
    Message("\r\n [+] STATE: WAITING FOR DMA ...");
    Message("\r\n [+] INIT DMA TRANSMISSION");
    /*
    MAP_UARTConfigSetExpClk(UARTA1_BASE,MAP_PRCMPeripheralClockGet(PRCM_UARTA1),
        UART_BAUD_RATE,
        (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
        UART_CONFIG_PAR_NONE));
	*/

    MAP_UARTEnable(UARTA1_BASE);

    UARTFIFOLevelSet(UARTA1_BASE,UART_FIFO_TX1_8,UART_FIFO_TX7_8); // LED
    UARTFIFOEnable(UARTA1_BASE); // LED

    Message("\r\n [+] FIFO DONE");

    while(1){ //  Breaks after one iteration ...
    UDMASetupPingPongTransfer(UDMA_CH11_UARTA1_TX,				// LED
    		(void *) LEDBuffer[0],
    		(void *) (UARTA1_BASE + UART_O_DR),
    		(void *) LEDBuffer[8],
    		(void *) (UARTA1_BASE + UART_O_DR),
                              8);
    Message("\r\n [+] PING PONG SET");

    MAP_uDMAChannelEnable(UDMA_CH11_UARTA1_TX);
    Message("\r\n [+] DMACHANNEL ENABLED");

    //MAP_UARTDMAEnable(UARTA0_BASE,UART_DMA_RX);
    MAP_UARTDMAEnable(UARTA1_BASE,UART_DMA_TX); // LED
    //Message("\r\n [+] DMA ENABLED");

    //UDMAStartTransfer(UDMA_CH11_UARTA1_TX); // LED

    //Message("\r\n [+] WAITING FOR TRANSMISSION");
    while(!bTxDone_1){    }
    }
}

Would be very pleased for any hints or help, 

best,  Vinc