change core clock to 25MHZ

Signed-off-by: liangkangnan <liangkangnan@163.com>

rtl/core/defines.sv

@@ -15,11 +15,11 @@
  */
 
 `define CPU_RESET_ADDR       32'h00000000                   // CPU复位地址
-`define CPU_CLOCK_HZ         50000000        // CPU时钟(50MHZ)
+`define CPU_CLOCK_HZ         25000000                       // CPU时钟(25MHZ)
 `define JTAG_RESET_FF_LEVELS 5
 
-`define ROM_DEPTH     8192                   // 指令存储器深度，单位为word(4字节)
-`define RAM_DEPTH     4096                   // 数据存储器深度，单位为word(4字节)
+`define ROM_DEPTH           (32 * 1024)                     // 指令存储器深度，单位为word(4字节)
+`define RAM_DEPTH           ( 8 * 1024)                     // 数据存储器深度，单位为word(4字节)
 
 // 外设地址、大小
 // ROM

sdk/bsp/link.lds

@@ -5,13 +5,13 @@ ENTRY(_start)
 MEMORY
 {
   flash (wxa!ri) : ORIGIN = 0x00000000, LENGTH = 32K
-  ram (wxa!ri) :   ORIGIN = 0x20000000, LENGTH = 16K
+  ram (wxa!ri) :   ORIGIN = 0x20000000, LENGTH = 8K
 }
 
 
 SECTIONS
 {
-   __stack_size = DEFINED(__stack_size) ? __stack_size : 8K;
+   __stack_size = DEFINED(__stack_size) ? __stack_size : 2K;
 
   .init           :
   {

sdk/examples/hello_world/main.c

@@ -1,13 +1,18 @@
 #include <stdint.h>
-#include "../../bsp/include/sim_ctrl.h"
-#include "../../bsp/include/xprintf.h"
 
+#include "../../bsp/include/sim_ctrl.h"
+#include "../../bsp/include/uart.h"
+#include "../../bsp/include/xprintf.h"
 
 
 
 int main()
 {
+#ifdef SIMULATION
     sim_ctrl_init();
+#else
+    uart_init();
+#endif
 
     xprintf("hello world\n");