// Bit Definitions
#define BIT0 0x01
#define BIT1 0x02
#define BIT2 0x04
#define BIT3 0x08
#define BIT4 0x10
#define BIT5 0x20
#define BIT6 0x40
#define BIT7 0x80
#define BIT8 0x100
#define BIT9 0x200
#define BIT10 0x400
#define BIT11 0x800
#define BIT12 0x1000
#define BIT13 0x2000
#define BIT14 0x4000
#define BIT15 0x8000


#include <Analogdevices/ioaduc7061.h>
# include "stdio.h"
# include "string.h"
#include <intrinsics.h>
#include <arm_interrupt.h>

volatile unsigned char bSendResultToUART = 0; // Flag used to indicate ADC0 resutl ready to send to UART
unsigned char szTemp[16] = ""; // Used to store ADC0 result before printing to UART
unsigned char ucTxBufferEmpty = 0; // Used to indicate that the UART Tx buffer is empty
volatile unsigned long ulADC0Result = 0; // Variable that ADC0DAT is read into in ADC0 IRQ
float V;

int main(void)
{

unsigned char i = 0;
unsigned char nLen = 0;


POWKEY1 = 0x1;
POWCON0 = 0x78; // Set core to max CPU speed of 10.24Mhz
POWKEY2 = 0xF4;

// Initialize the UART for 9600-8-N
GP1CON = BIT0 + BIT4; // Select UART functionality for P1.0/P1.1
COMCON0 = BIT7; // Enable access to COMDIV registers
COMDIV0 = 0x21; // Set baud rate to 9600.
COMDIV1 = 0x00;
//COMDIV2 = 0x21 + BIT11; // Enable fractional divider for more accurate baud rate setting
COMCON0 = BIT0 + BIT1 + BIT2;
COMIEN0 = BIT0 + BIT1; // Enable UART interrupts when Rx full and Tx buffer empty.


// Configure ADC0 for continuous conversions, 1Khz, AIN0 in Single-ended mode
ADCMSKI = BIT0; // Enable ADC0 result ready interrupt source
ADCFLT = 0x7; // Chop off, 1Khz samping rate, SF = 7. No averaging
ADCMDE = BIT0 + BIT7; // Continuous Conversion mode, Normal mode, 4Mhz clock source to ADC.
ADC0CON =

BIT4 +
BIT6 + BIT7 + BIT8 + // AIN0 selected in Single ended mode

BIT10 + // Unipolar ADC output
BIT15; // Gain = 1, Buffer on. Also, Int reference,

ADCCFG = 0;
IRQEN = BIT10 + BIT11; // Enable ADC and UART interrupts
__enable_interrupt();

bSendResultToUART = 0;
while (1)
{

if (bSendResultToUART == 1) // Is there an ADC0 result ready for UART transmission?
{

sprintf ( (char*)szTemp, "%lu\r",ulADC0Result ); // Send the ADC0 Result to the UART
nLen = strlen((char*)szTemp);
for ( i = 0 ; i < nLen ; i++ ) // loop to send ADC0 result
{

COMTX = szTemp[i];
ucTxBufferEmpty = 0;
while (ucTxBufferEmpty == 0)

}

}
}

}
#pragma vector = 0x18
__irq __arm void IRQ_Handler(void)
{

unsigned long IRQSTATUS = 0;
unsigned char ucCOMIID0 = 0;

IRQSTATUS = IRQSTA; // Read off IRQSTA register
if ((IRQSTATUS & BIT11) == BIT11) //UART interrupt source
{

ucCOMIID0 = COMIID0;
if ((ucCOMIID0 & 0x2) == 0x2) // Transmit buffer empty
{
ucTxBufferEmpty = 1;
}

}

if ((IRQSTATUS & BIT10) == BIT10) //If ADC0 interrupt source
{

ulADC0Result = ADC0DAT; // Read ADC0 conversion result
bSendResultToUART = 1;

}

}

Оказалось, причина умолкания UARTа в том, что регистр COMRX нигде не считывался, соответственно, флаг прерывания по приему не сбрасывался и программа крутилась в прерывании по UART. Вот, что добавил:

if ((ucCOMIID0 & 0x4) == 0x4) // Receive buffer empty
{
V=COMRX;
}

    COMTX = szTemp[i];
    ucTxBufferEmpty = 0;
   while (ucTxBufferEmpty == 0);

    ucTxBufferEmpty = 0;
    COMTX = szTemp[i];
    while (ucTxBufferEmpty == 0);

    while (ucTxBufferBusy == 1);
    ucTxBufferBusy = 1;
    COMTX = szTemp[i];