diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index 2ee85c8..6837ea6 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -184,6 +184,8 @@ void HardwareSerial::begin(
 
         crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);
         crm_periph_clock_enable(CRM_USART6_PERIPH_CLOCK, TRUE);
+        crm_periph_clock_enable(CRM_IOMUX_PERIPH_CLOCK, TRUE);
+        gpio_pin_remap_config(USART6_GMUX, TRUE);
     }
     else if (_USARTx == UART7)
     {
@@ -214,13 +216,19 @@ void HardwareSerial::begin(
         return;
     }
 
-    gpio_default_para_init(&gpio_init_struct);
-    gpio_init_struct.gpio_pins =  Tx_Pin | Rx_Pin;
-    gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
-    gpio_init_struct.gpio_mode = GPIO_MODE_MUX;
-    gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
-    gpio_init_struct.gpio_out_type  = GPIO_OUTPUT_PUSH_PULL;
-    gpio_init(GPIOx, &gpio_init_struct);
+	gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
+	gpio_init_struct.gpio_out_type  = GPIO_OUTPUT_PUSH_PULL;
+	gpio_init_struct.gpio_mode = GPIO_MODE_MUX;
+	gpio_init_struct.gpio_pins = Tx_Pin;
+	gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
+	gpio_init(GPIOx, &gpio_init_struct);
+	
+	gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
+	gpio_init_struct.gpio_out_type  = GPIO_OUTPUT_PUSH_PULL;
+	gpio_init_struct.gpio_mode = GPIO_MODE_INPUT;
+	gpio_init_struct.gpio_pins = Rx_Pin;
+	gpio_init_struct.gpio_pull = GPIO_PULL_UP;
+	gpio_init(GPIOx, &gpio_init_struct);
 
     usart_init(_USARTx, baudRate, SERIAL_ConfigGrp[config].data_bit, SERIAL_ConfigGrp[config].stop_bit);
     usart_parity_selection_config(_USARTx, SERIAL_ConfigGrp[config].parity_selection);
diff --git a/cores/arduino/HardwareSerial.h b/cores/arduino/HardwareSerial.h
index 72ae6b6..8347be8 100644
--- a/cores/arduino/HardwareSerial.h
+++ b/cores/arduino/HardwareSerial.h
@@ -138,9 +138,11 @@ extern HardwareSerial Serial5;
 #if SERIAL_6_ENABLE
 extern HardwareSerial Serial6;
 #endif
+
 #if SERIAL_7_ENABLE
 extern HardwareSerial Serial7;
 #endif
+
 #if SERIAL_8_ENABLE
 extern HardwareSerial Serial8;
 #endif
diff --git a/cores/arduino/libcore/gpio.c b/cores/arduino/libcore/gpio.c
index ba625b5..8000ba5 100644
--- a/cores/arduino/libcore/gpio.c
+++ b/cores/arduino/libcore/gpio.c
@@ -270,8 +270,8 @@ void GPIOx_Init(
   */
 void GPIO_JTAG_Disable(void)
 {
-//    RCC_APB2PeriphClockCmd(RCC_APB2PERIPH_AFIO, ENABLE);
-//    GPIO_PinsRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
+    crm_periph_clock_enable(CRM_IOMUX_PERIPH_CLOCK, TRUE);
+    gpio_pin_remap_config(SWJTAG_GMUX_010, TRUE);
 }
 
 /**
diff --git a/cores/arduino/libcore/mcu_core.c b/cores/arduino/libcore/mcu_core.c
index 128e6a7..c398682 100644
--- a/cores/arduino/libcore/mcu_core.c
+++ b/cores/arduino/libcore/mcu_core.c
@@ -27,7 +27,7 @@ void Core_Init(void)
 {
     system_clock_config();
     nvic_priority_group_config(NVIC_PRIORITY_GROUP_2);
-//    GPIO_JTAG_Disable();
+    GPIO_JTAG_Disable();
     Delay_Init();
     ADCx_Init(ADC1);
 }
diff --git a/package_at32_index.json b/package_at32_index.json
index dafcd3b..8e50268 100644
--- a/package_at32_index.json
+++ b/package_at32_index.json
@@ -12,7 +12,7 @@
         {
           "name": "AT32F403ACGU7 Core Board",
           "architecture": "at32f403a",
-          "version": "0.0.8",
+          "version": "0.0.9",
           "category": "Contributed",
           "url": "https://github.com/WeActStudio/ArduinoCore-AT32F4/archive/refs/heads/main.zip",
           "archiveFileName": "ArduinoCore-AT32F4-main.zip",
diff --git a/platform.txt b/platform.txt
index 8defd69..3cdcfb0 100644
--- a/platform.txt
+++ b/platform.txt
@@ -1,6 +1,6 @@
 ##==============================================##
 name=WeActStudio AT32F403A Boards
-version=0.0.8
+version=0.0.9
 ##==============================================##
 
 ####AT32 compile variables