V2.0

EVT/EXAM/USART/USART_HalfDuplex/User/ch32v20x_it.c

@@ -2,7 +2,7 @@
  * File Name          : ch32v20x_it.c
  * Author             : WCH
  * Version            : V1.0.0
- * Date               : 2021/06/06
+ * Date               : 2023/12/29
  * Description        : Main Interrupt Service Routines.
 *********************************************************************************
 * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
@@ -23,6 +23,9 @@ void HardFault_Handler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
  */
 void NMI_Handler(void)
 {
+  while (1)
+  {
+  }
 }
 
 /*********************************************************************

EVT/EXAM/USART/USART_HalfDuplex/User/main.c

@@ -2,7 +2,7 @@
  * File Name          : main.c
  * Author             : WCH
  * Version            : V1.0.0
- * Date               : 2021/06/06
+ * Date               : 2024/01/06
  * Description        : Main program body.
  *********************************************************************************
  * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
@@ -19,8 +19,9 @@
  *This example demonstrates UART2 and USART3 single-wire half-duplex mode data
  *transmission and reception.
  *
- *    Hardware connection:PA2 -- PB10
- *
+ *Hardware connection:PA2 -- PB10
+ *Note: The pin should be GPIO_Mode_AF_OD in single-wire half-duplex mode.
+ *      The pin needs to connected a pull_up resistor 
  */
 
 #include "debug.h"
@@ -91,7 +92,7 @@ void USARTx_CFG(void)
     /* USART2 TX-->A.2 */
     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; /* Only Configure TX Pin */
     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
-    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
     GPIO_Init(GPIOA, &GPIO_InitStructure);
 
     /* USART3 TX-->B.10 */
@@ -122,7 +123,7 @@ void USARTx_CFG(void)
  */
 int main(void)
 {
-    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
+    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
     SystemCoreClockUpdate();
     Delay_Init();
     USART_Printf_Init(115200);

EVT/EXAM/USART/USART_HalfDuplex/User/system_ch32v20x.c

@@ -111,10 +111,10 @@ static void SetSysClockTo144_HSI( void );
 void SystemInit (void)
 {
   RCC->CTLR |= (uint32_t)0x00000001;
-  RCC->CFGR0 &= (uint32_t)0xF8FF0000;
+  RCC->CFGR0 &= (uint32_t)0xF0FF0000;
   RCC->CTLR &= (uint32_t)0xFEF6FFFF;
   RCC->CTLR &= (uint32_t)0xFFFBFFFF;
-  RCC->CFGR0 &= (uint32_t)0xFF80FFFF;
+  RCC->CFGR0 &= (uint32_t)0xFF00FFFF;
   RCC->INTR = 0x009F0000;    
   SetSysClock();
 }