Stair56E UART project

2026-08-05 19:07:52 +08:00
parent 7ca1af130d
commit f5654b70cc
2500 changed files with 619007 additions and 282610 deletions
@@ -0,0 +1,79 @@
+
+#include "Includes.h"
+
+void retarget_init(void)
+{
+    unsigned int val;
+    __read_hw_reg32(CPR_GPIO_FUN_SEL4, val);
+    val &= 0xFFFF;
+    /* GPIO18: TX; GPIO19: RX */
+    val |= ((1 << 16) | (2 << 24));
+    __write_hw_reg32(CPR_GPIO_FUN_SEL4, val);
+    /* Reset uart module */
+    __write_hw_reg32(CPR_RSTCTL_SUBRST_SW, 0x10000);
+    /* Unreset uart module */
+    __write_hw_reg32(CPR_RSTCTL_SUBRST_SW, 0x10001);
+    /* Enable uart0 pclk */
+    __write_hw_reg32(CPR_CTLAPBCLKEN_GRCTL, 0x100010);
+    /* Set the first-level division ratio of uart0_clk relative to the 12MHz clock */
+    __write_hw_reg32(CPR_UART0_CLK_GRCTL, 0x110018);
+    /* Set the secondary frequency division coefficient of uart0_clk relative to the 12MHz clock */
+    //__write_hw_reg32(CPR_UART0_CLK_CTL, 0x0600271);//57600-OSC12M
+    __write_hw_reg32(CPR_UART0_CLK_CTL, 0x0480271); // 115200-OSC32M
+    //__write_hw_reg32(CPR_UART0_CLK_CTL, 0x1800271);//230400-OSC12M
+    //__write_hw_reg32(CPR_UART0_CLK_CTL, 0x0C00271);//115200-OSC12M
+    /* Enable DLAB */
+    __write_hw_reg32(UART0_TCR, 0x80);
+    /* Control the baud rate */
+    __write_hw_reg32(UART0_DLL, 0x01);
+    /* Control the baud rate */
+    __write_hw_reg32(UART0_DLH, 0x00);
+    /* Set the data bit of the serial port */
+    __write_hw_reg32(UART0_TCR, 0x03);
+    /* Set the interrupt threshold of transmit FIFO and receive FIFO and Clear the transmit and receive FIFO, Finally enable FIFO */
+    __write_hw_reg32(UART0_FCR, 0x37);
+    printf("\n SYSTEM BUILD TIME: %s %s \n", __DATE__, __TIME__);
+}
+
+int sendchar(int c)
+{
+    //return 0;
+    unsigned int status;
+    for (;;)
+    {
+        status = (*((volatile unsigned *)(0x40010000 + 0x14)));
+        status &= 0x20;
+        if (status == 0x20)
+            break;
+    }
+    (*((volatile unsigned *)(0x40010000 + 0x00))) = c;
+    return (1);
+}
+
+struct __FILE
+{
+    int handle; /* Add whatever you need here */
+};
+FILE __stdout;
+
+int fputc(int ch, FILE *f)
+{
+    return (sendchar(ch));
+}
+
+int ferror(FILE *f)
+{
+    /* Your implementation of ferror */
+    return EOF;
+}
+
+void _ttywrch(int ch)
+{
+    sendchar(ch);
+}
+
+void _sys_exit(int return_code)
+{
+label:
+    goto label; /* endless loop */
+}