KEAZ128-UART-S32DS

/*
 * main implementation: use this 'C' sample to create your own application
 *
 */


#include "derivative.h" /* include peripheral declarations SSKEAZ128M4 */
#include "uart.h"
#include "nvic.h"
UART_ConfigType *pConfig;

void Clk_Init_20Mhz()
 {
     ICS_C1|=ICS_C1_IRCLKEN_MASK; /* Enable the internal reference clock*/
     ICS_C3= 0x90; /* Reference clock frequency = 31.25 kHz*/
     while(!(ICS_S & ICS_S_LOCK_MASK)); /* Wait for PLL lock, now running at 40 MHz (1280
     *31.25 kHz) */
     ICS_C2|=ICS_C2_BDIV(1) ; /*BDIV=2, Bus clock = 20 MHz*/
     ICS_S |= ICS_S_LOCK_MASK ; /* Clear Loss of lock sticky bit */
 }

void UART_Init_marvin ()
 {
     SIM_SCGC |= SIM_SCGC_UART2_MASK; /* Enable bus clock in UART2  UART2PS=0 PTD7 TX,PTD6 RX*/
     UART2_BDH = 0; /* One stop bit*/
     UART2_BDL = 128; /* Baud rate at 9600*/
     UART2_C1 = 0; /* No parity enable,8-bit format*/
     UART2_C2 |= UART_C2_TE_MASK; /* Enable Transmitter*/
     UART2_C2 |= UART_C2_RE_MASK; /* Enable Receiver*/
     UART2_C2 |= UART_C2_RIE_MASK; /* Enable Receiver interrupts*/
 }

void delay500ms(void)

{
unsigned char i,j,k;
for(i=15;i>0;i--)
    for(j=202;j>0;j--)
        for(k=81;k>0;k--);
}


int main(void)
{

    Clk_Init_20Mhz();
    UART_Init_marvin();
    Enable_Interrupt(UART2_IRQn);

        for(;;) {
            delay500ms();
            while((UART2_S1 & UART_S1_TDRE_MASK)==0);/* Wait for transmit buffer to be
empty*/
            (void)UART2_S1; /* Read UART2_S1 register*/
             UART2_D= '2'; /* Send data*/

        }

    /* to avoid the warning message for GHS: statement is unreachable*/
#if defined (__ghs__)
#pragma ghs nowarning 111
#endif
#if defined (__ICCARM__)
#pragma diag_suppress=Pe111
#endif
    return 0;
}

void UART2_SCI2_IRQHandler ()
 {
//   char data = 0;
//   (void)UART2_S1; /* Clear reception flag mechanism*/
//   data = UART2_D; /* Receive data*/
 }

使用PL2102的usb串口模块（其他芯片不兼容，出乱码），模块的RX接单片机的22脚D7（uart2的tx）

使用自带的kea128的库，调试器选择segger

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https://www.nxp.com.cn/docs/en/application-note/AN4942.pdf
参考这个网址操作uart和clk的设置
注意这个pdf使用了没有定义的寄存器名称，通过使用uart.h里的中断使能函数替换下图中的两行代码

image.png image.png