diff --git a/variants/elsomik/variant.c b/variants/elsomik/variant.c
index cff665c..a80a567 100644
--- a/variants/elsomik/variant.c
+++ b/variants/elsomik/variant.c
@@ -45,7 +45,7 @@ __attribute__((noinline, section(".ram_text"))) HAL_PinsTypeDef digitalPinToBitM
   if (digitalPinNumber >= PINS_COMMON_QTY)
   {
     ErrorMsgHandler("digitalPinToBitMask(): pin number exceeds the total number of pins");
-    return NC;
+    return NOT_A_PIN;
   }
 
   if (digitalPinNumber >= P2_6)
diff --git a/variants/start/pins_arduino.h b/variants/start/pins_arduino.h
index cbca102..f785196 100644
--- a/variants/start/pins_arduino.h
+++ b/variants/start/pins_arduino.h
@@ -78,6 +78,9 @@ typedef enum
   PINS_COMMON_QTY,  // 40
 } DigitalPinsTypeDef;
 
+// total number of pins available for initialization
+#define pinCommonQty()    (PINS_COMMON_QTY)
+
 // analog pins
 #define PIN_A0        (P1_5)
 #define PIN_A1        (P1_7)
@@ -108,11 +111,6 @@ static const uint8_t A7 = PIN_A7;
 GPIO_TypeDef* digitalPinToPort(uint32_t digPinNumber);     
 // determines the pin address inside the port by the board pin number
 HAL_PinsTypeDef digitalPinToBitMask(uint32_t digitalPinNumber);
-// total number of pins available for initialization
-static inline uint16_t pinCommonQty(void)
-{
-  return (uint16_t)PINS_COMMON_QTY;
-}
 // the function returns a reference to the OUTPUT address of the GPIO register
 volatile uint32_t* portOutputRegister(GPIO_TypeDef* GPIO_x);
 // the function returns a reference to the STATE address of the GPIO register
@@ -132,8 +130,12 @@ uint32_t analogInputToChannelNumber(uint32_t PinNumber);
 
 // PWM
 #define PWM_FREQUENCY_MAX         1000000 // Hz
-bool digitalPinHasPWM(uint8_t p);
-bool digitalPinPwmIsOn(uint8_t digitalPin); // use only if digitalPinHasPWM() == true
+static inline __attribute__((always_inline)) bool digitalPinHasPWM(uint8_t p)
+{
+  return (p < 32) && ((p & 0xF) < 4);
+}
+// return true if digitalPin configured as pwm
+bool digitalPinPwmIsOn(uint8_t digitalPin);
 // determines which timer the pin belongs to
 TIMER32_TypeDef* pwmPinToTimer(uint32_t digPinNumber);
 // determines which timer channel the pin belongs to
diff --git a/variants/start/variant.c b/variants/start/variant.c
index dbd66cb..0179517 100644
--- a/variants/start/variant.c
+++ b/variants/start/variant.c
@@ -21,7 +21,7 @@
  * @return The address of the port corresponding to the board pin number. Can return 0 if the pin not exists
  */
 
-GPIO_TypeDef *digitalPinToPort(uint32_t digitalPinNumber)
+ __attribute__((noinline, section(".ram_text"))) GPIO_TypeDef *digitalPinToPort(uint32_t digitalPinNumber)
 {
   GPIO_TypeDef* port = NULL;
   if (digitalPinNumber < pinCommonQty())
@@ -39,12 +39,12 @@ GPIO_TypeDef *digitalPinToPort(uint32_t digitalPinNumber)
 }
 
 // determines the pin address inside the port by the board pin number
-HAL_PinsTypeDef digitalPinToBitMask(uint32_t digitalPinNumber)
+__attribute__((noinline, section(".ram_text"))) HAL_PinsTypeDef digitalPinToBitMask(uint32_t digitalPinNumber)
 {
   if (digitalPinNumber >= pinCommonQty())
   {
     ErrorMsgHandler("digitalPinToBitMask(): pin number exceeds the total number of pins");
-    return NC;
+    return NOT_A_PIN;
   }
 
   return (HAL_PinsTypeDef)(1 << (digitalPinNumber & 0xF));
@@ -108,25 +108,22 @@ uint32_t analogInputToChannelNumber(uint32_t PinNumber)
 // return true if digitalPin configured as pwm
 bool digitalPinPwmIsOn(uint8_t digitalPin)
 {
-  uint8_t config = 0;
-  uint8_t pinShift = digitalPin & 3;
+  if (digitalPinHasPWM(digitalPin))
+  {
+    uint8_t config = 0;
+    uint8_t pinShift = digitalPin & 3;
 
-  if (PWM_PIN_TO_PORT_NUMBER(digitalPin) == 0)
-    config = PIN_GET_PAD_CONFIG(PORT_0_CFG, pinShift);
-  else
-    config = PIN_GET_PAD_CONFIG(PORT_1_CFG, pinShift);
+    if (PWM_PIN_TO_PORT_NUMBER(digitalPin) == 0)
+      config = PIN_GET_PAD_CONFIG(PORT_0_CFG, pinShift);
+    else
+      config = PIN_GET_PAD_CONFIG(PORT_1_CFG, pinShift);
 
-  if (config == 2)
-    return true;
-  else
+    if (config == 2)
+      return true;
+  }
     return false;
 }
 
-bool digitalPinHasPWM(uint8_t p)
-{
-  return (p < 32) && ((p & 0xF) < 4);
-}
-
 // function is used only if digitalPinHasPWM() is true
 TIMER32_TypeDef *pwmPinToTimer(uint32_t digPinNumber)
 {