diff --git a/cores/arduino/WInterrupts.c b/cores/arduino/WInterrupts.c
index 64bf587..78bcd08 100644
--- a/cores/arduino/WInterrupts.c
+++ b/cores/arduino/WInterrupts.c
@@ -19,13 +19,13 @@ static void nothing(void)
 // enable global interrupts
 void interrupts(void)
 {
-  HAL_IRQ_EnableInterrupts();
+  GLOBAL_IRQ_ENABLE();
 }
 
 // disable global interrupts
 void noInterrupts(void)
 {
-  HAL_IRQ_DisableInterrupts();
+  GLOBAL_IRQ_DISABLE();
 }
 
 // we can provide no more than 8 interrupts on gpio at the same time
diff --git a/cores/arduino/board.cpp b/cores/arduino/board.cpp
index 4b06378..04bfa4c 100644
--- a/cores/arduino/board.cpp
+++ b/cores/arduino/board.cpp
@@ -27,8 +27,6 @@ void post_init(void)
 {
     // enable global interrupts by default
     interrupts();
-
-    ((GPIO_0)->SET = (GPIO_PIN_0));
 }
 
 // --------------------- other --------------------- // 
diff --git a/cores/arduino/trap_handler.c b/cores/arduino/trap_handler.c
index 712913c..9e6fc21 100644
--- a/cores/arduino/trap_handler.c
+++ b/cores/arduino/trap_handler.c
@@ -1,4 +1,5 @@
 #include "mik32_hal_irq.h" 
+#include "wiring_LL.h" 
 
 // isr functions
 extern void serial_handler_wrapper(uint8_t uartNumInt);
@@ -33,5 +34,5 @@ void __attribute__((noinline, section(".ram_text"))) trap_handler(void)
         wire_handler_wrapper();
 
     // reset all interrupts
-    HAL_EPIC_Clear(0xFFFFFFFF);
+    EPIC_CLEAR_ALL();
 }
diff --git a/cores/arduino/wiring_LL.h b/cores/arduino/wiring_LL.h
index 84ba3c7..a635e5f 100644
--- a/cores/arduino/wiring_LL.h
+++ b/cores/arduino/wiring_LL.h
@@ -4,30 +4,57 @@
 #include "mik32_hal_irq.h" 
 #include "mik32_hal_gpio.h"
 #include "mik32_hal_scr1_timer.h"
+#include "mik32_hal_timer16.h"
 
-// ----------------- Systick ----------------- //
+// ----------------- COMMON ----------------- //
+// convert pin mask from HAL_PinsTypeDef to pin number
+#define PIN_MASK_TO_PIN_NUMBER(mask)    \
+({                                      \
+  uint8_t pos;                          \
+  for (pos = 0; pos < 16; pos++)        \
+    if ((mask >> pos) & 1)              \
+      break;                            \
+  pos;                                  \
+})
+
+// ----------------- SYSTICK ----------------- //
 // get ticks from systick
-#define SYSTICK_GET_TICKS()     ((uint64_t)(SCR1_TIMER->MTIMEH)<<32 | SCR1_TIMER->MTIME)
+#define SYSTICK_GET_TICKS()                     ((uint64_t)(SCR1_TIMER->MTIMEH)<<32 | SCR1_TIMER->MTIME)
 
+// ----------------- TIMER16 ----------------- //
+#define TIM16_DISABLE(htim16)                   (htim16.Instance->CR &= ~TIMER16_CR_ENABLE_M)
+#define TIM16_CLEAR_INT_MASK(htim16, intMask)   (htim16.Instance->ICR = intMask)
+#define TIM16_GET_ARRM_INT_STATUS(htim16)       ((bool)((htim16.Instance->ISR & htim16.Instance->IER) & TIMER16_ISR_ARR_MATCH_M))
+
+// ----------------- EPIC ----------------- //
+#define EPIC_LEVEL_CLEAR_BY_MASK(mask)          (EPIC->MASK_LEVEL_CLEAR |= mask)
+#define EPIC_CLEAR_ALL()                        (EPIC->CLEAR = 0xFFFFFFFF)
 
 // ----------------- IRQ ----------------- //
-#define GLOBAL_IRQ_DISABLE()    (clear_csr(mie, MIE_MEIE))
-#define GLOBAL_IRQ_ENABLE()     set_csr(mstatus, MSTATUS_MIE); \
-                                set_csr(mie, MIE_MEIE)
+#define GLOBAL_IRQ_DISABLE()                    (clear_csr(mie, MIE_MEIE))
+#define GLOBAL_IRQ_ENABLE()                     set_csr(mstatus, MSTATUS_MIE); \
+                                                set_csr(mie, MIE_MEIE)
 
 // ----------------- GPIO ----------------- //
-#define GPIO_SET_PIN(GPIO_x, pin)           ((GPIO_x)->SET = (pin))
-#define GPIO_CLEAR_PIN(GPIO_x, pin)         ((GPIO_x)->CLEAR = (pin))
-#define GPIO_READ_PIN(GPIO_x, pin)          (((GPIO_x)->SET & (pin)) != (uint32_t)GPIO_PIN_LOW ? GPIO_PIN_HIGH : GPIO_PIN_LOW)
+#define GPIO_SET_PIN(GPIO_x, pinMask)           ((GPIO_x)->SET = (pinMask))
+#define GPIO_CLEAR_PIN(GPIO_x, pinMask)         ((GPIO_x)->CLEAR = (pinMask))
+#define GPIO_TOGGLE_PIN(GPIO_x, pinMask)        ((GPIO_x)->OUTPUT_ ^= pinMask)
+#define GPIO_READ_PIN(GPIO_x, pinMask)          (((GPIO_x)->SET & (pinMask)) != (uint32_t)GPIO_PIN_LOW ? GPIO_PIN_HIGH : GPIO_PIN_LOW)
+// get pin state by it's number
+#define GPIO_GET_PIN_STATE(GPIO_x, pinNumber)   (((GPIO_x)->OUTPUT_ >> pinNumber) & 0b1)
 
 // ----------------- GPIO IRQ ----------------- //
-#define GPIO_IRQ_LINE_ENABLE(lineMask)      ( GPIO_IRQ->ENABLE_SET = (1 << (lineMask >> GPIO_IRQ_LINE_S)) )
-#define GPIO_IRQ_LINE_DISABLE(lineMask)     ( GPIO_IRQ->ENABLE_CLEAR = (1 << (lineMask >> GPIO_IRQ_LINE_S)) )
-#define GPIO_IRQ_LINE_STATE(lineMask)       ((GPIO_IRQ->INTERRUPT & (1 << (lineMask >> GPIO_IRQ_LINE_S))) != 0)
-#define GPIO_IRQ_CLEAR_ALL()                ( GPIO_IRQ->CLEAR = 0b11111111)
+#define GPIO_IRQ_LINE_ENABLE(lineMask)          ( GPIO_IRQ->ENABLE_SET = (1 << (lineMask >> GPIO_IRQ_LINE_S)) )
+#define GPIO_IRQ_LINE_DISABLE(lineMask)         ( GPIO_IRQ->ENABLE_CLEAR = (1 << (lineMask >> GPIO_IRQ_LINE_S)) )
+#define GPIO_IRQ_LINE_STATE(lineMask)           ((GPIO_IRQ->INTERRUPT & (1 << (lineMask >> GPIO_IRQ_LINE_S))) != 0)
+#define GPIO_IRQ_CLEAR_ALL()                    ( GPIO_IRQ->CLEAR = 0b11111111)
 
 // ----------------- PIN CONFIG ----------------- //
-// return config of pin with pinShift(0...16) in portReg (config, pupd, ds for ports 0...2)
-#define PIN_GET_PAD_CONFIG(portReg, pinShift)   ((PAD_CONFIG->portReg  >> (pinShift<<1)) & 0b11)
+// return config of pin with pinNumber(0...16) in portReg (config, pupd, ds for ports 0...2)
+#define PIN_GET_PAD_CONFIG(portReg, pinNumber)          ((PAD_CONFIG->portReg  >> (pinNumber<<1)) & 0b11)
+#define PIN_SET_PAD_CONFIG(portReg, pinNumber, value)   (PAD_CONFIG->portReg = (PAD_CONFIG->portReg & (~PAD_CONFIG_PIN_M(pinNumber))) \
+                                                        | PAD_CONFIG_PIN(pinNumber, value))
+
+  
 
 #endif /* _WIRING_LL_H_ */
\ No newline at end of file
diff --git a/libraries/SoftwareSerial/src/SoftwareSerial.cpp b/libraries/SoftwareSerial/src/SoftwareSerial.cpp
index 18d9b41..001eb0b 100644
--- a/libraries/SoftwareSerial/src/SoftwareSerial.cpp
+++ b/libraries/SoftwareSerial/src/SoftwareSerial.cpp
@@ -198,10 +198,15 @@ void SoftwareSerial::setRX(uint8_t rx)
 
   // attach interrupt to rx pin if available
   attachInterrupt(digitalPinToInterrupt(_receivePin), softSerial_handler_wrapper, _inverse_logic ? RISING : FALLING);
+  // turn on pull up for rx if logic is not inverse
   if (!_inverse_logic)
-    // turn on pull up for rx if logic is not inverse
-    HAL_GPIO_PinConfig((GPIO_TypeDef *)_receivePortRegister, (HAL_PinsTypeDef)_receiveBitMask, 
-                      HAL_GPIO_MODE_GPIO_INPUT, HAL_GPIO_PULL_UP, HAL_GPIO_DS_2MA);
+  {
+    uint8_t pinNumber = PIN_MASK_TO_PIN_NUMBER(_receiveBitMask);
+    if (((GPIO_TypeDef*)_receivePortRegister) == GPIO_0)
+      PIN_SET_PAD_CONFIG(PORT_0_PUPD, pinNumber, HAL_GPIO_PULL_UP);
+    else if (((GPIO_TypeDef*)_receivePortRegister) == GPIO_1)
+      PIN_SET_PAD_CONFIG(PORT_1_PUPD, pinNumber, HAL_GPIO_PULL_UP);
+  }
   // turn off int line for while (it turning on in attachInterrupt())
   GPIO_IRQ_LINE_DISABLE(_int_maskLine);
 }