my AT91SAM9G45 board DBGUART can not print out,DEBUG at91bootstrap-at91sam9g45-ek-iar source #if defined(TRACE_DBGU) DEBUG cannot print out,#lif defined(TRACE_USART_2) UART2 print out normal.why?

I have never had an issue with my DEBUG port as long as it was initialized and configured for the correct baud rate.

Here is my init code (Note: I don't use IAR but the Atmel Config file should be similar)

/* Write DBGU register */
static inline void write_dbgu(unsigned int offset, const unsigned int value)
{
writel(value, offset + AT91C_BASE_DBGU);
}

/* Read DBGU registers */
static inline unsigned int read_dbgu( unsigned int offset)
{
return readl(offset + AT91C_BASE_DBGU);
}

/* Disable interrupts */
write_dbgu(US_IDR, -1);
/* Reset the receiver and transmitter */
write_dbgu(US_CR, AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RXDIS | AT91C_US_TXDIS);
#if (MASTER_CLOCK == 133333333)
/* Configure the baudrate 115200 = 133333333 / 16 * CD */
write_dbgu(US_BRGR, 72);
#else
/* Configure the baudrate 115200 = 100000000 / 16 * CD */
write_dbgu(US_BRGR, 54);
#endif
/* Configure USART in Asynchronous mode */
write_dbgu(US_MR, AT91C_US_PAR);
/* Enable RX and Tx */
write_dbgu(US_CR, AT91C_US_RXEN | AT91C_US_TXEN);