大神帮我看看这个延时为什么没起作用？

已经延时这么大了，但是串口还是跟没有延时一样，发得很快。

#include "cc430x513x.h"
#define uint8 unsigned char
#define uint16 unsigned int
void Delay(void)
{
unsigned int i,j;
for(i=0;i<50000;i++)
for(j=0;j<50000;j++);
}
void main(void)
{
uint8 ASCII_Number = 0;
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
PMAPPWD = 0x02D52; // Get write-access to port mapping regs
P2MAP6 = PM_UCA0RXD; // Map UCA0RXD output to P2.6
P2MAP7 = PM_UCA0TXD; // Map UCA0TXD output to P2.7
PMAPPWD = 0; // Lock port mapping registers
P2DIR |= BIT7; // Set P2.7 as TX output
P2SEL |= BIT6 + BIT7; // Select P2.6 & P2.7 to UART function
UCA0CTL1 |= UCSWRST; // **Put state machine in reset**
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 9; // 1MHz 115200 (see User's Guide)
UCA0BR1 = 0; // 1MHz 115200
UCA0MCTL |= UCBRS_1 + UCBRF_0; // Modulation UCBRSx=1, UCBRFx=0
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt
while(1)
{
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF = ASCII_Number; //
Delay();
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF = '\n'; //
Delay();
if(ASCII_Number<127)
ASCII_Number++;
else
ASCII_Number = 0;
}
}