diff --git a/driver/st7565.c b/driver/st7565.c
index dc6b125..af17e24 100644
--- a/driver/st7565.c
+++ b/driver/st7565.c
@@ -47,80 +47,78 @@ void ST7565_DrawLine(const unsigned int Column, const unsigned int Line, const u
 }
 
 
-// Optimization
-//
-// ST7565_BlitScreen(0) = ST7565_BlitStatusLine()
-// ST7565_BlitScreen(1..7) = ST7565_BlitLine()
-// ST7565_BlitScreen(8) = ST7565_BlitFullScreen()
-//
+#ifdef ENABLE_FEAT_F4HWN
+	// Optimization
+	//
+	// ST7565_BlitScreen(0) = ST7565_BlitStatusLine()
+	// ST7565_BlitScreen(1..7) = ST7565_BlitLine()
+	// ST7565_BlitScreen(8) = ST7565_BlitFullScreen()
+	//
 
-static void ST7565_BlitScreen(uint8_t line)
-{
-	SPI_ToggleMasterMode(&SPI0->CR, false);
-	ST7565_WriteByte(0x40);
+	static void ST7565_BlitScreen(uint8_t line)
+	{
+		SPI_ToggleMasterMode(&SPI0->CR, false);
+		ST7565_WriteByte(0x40);
 
-	if(line == 0)
-	{
-		DrawLine(0, 0, gStatusLine, LCD_WIDTH);
-	}
-	else if(line <= FRAME_LINES)
-	{
-		DrawLine(0, line, gFrameBuffer[line - 1], LCD_WIDTH);
-	}
-	else
-	{
-		for (line = 1; line <= FRAME_LINES; line++) {
+		if(line == 0)
+		{
+			DrawLine(0, 0, gStatusLine, LCD_WIDTH);
+		}
+		else if(line <= FRAME_LINES)
+		{
 			DrawLine(0, line, gFrameBuffer[line - 1], LCD_WIDTH);
 		}
+		else
+		{
+			for (line = 1; line <= FRAME_LINES; line++) {
+				DrawLine(0, line, gFrameBuffer[line - 1], LCD_WIDTH);
+			}
+		}
+
+		SPI_ToggleMasterMode(&SPI0->CR, true);
 	}
 
-	SPI_ToggleMasterMode(&SPI0->CR, true);
-}
+	void ST7565_BlitFullScreen(void)
+	{
+		ST7565_BlitScreen(8);
+	}
 
-void ST7565_BlitFullScreen(void)
-{
-	ST7565_BlitScreen(8);
-}
+	void ST7565_BlitLine(unsigned line)
+	{
+		ST7565_BlitScreen(line + 1);
+	}
 
-void ST7565_BlitLine(unsigned line)
-{
-	ST7565_BlitScreen(line + 1);
-}
+	void ST7565_BlitStatusLine(void)
+	{
+		ST7565_BlitScreen(0);
+	}
+#else
+	void ST7565_BlitFullScreen(void)
+	{
+		SPI_ToggleMasterMode(&SPI0->CR, false);
+		ST7565_WriteByte(0x40);
+		for (unsigned line = 0; line < FRAME_LINES; line++) {
+			DrawLine(0, line+1, gFrameBuffer[line], LCD_WIDTH);
+		}
+		SPI_ToggleMasterMode(&SPI0->CR, true);
+	}
 
-void ST7565_BlitStatusLine(void)
-{
-	ST7565_BlitScreen(0);
-}
-
-/*
-void ST7565_BlitFullScreen(void)
-{
-	SPI_ToggleMasterMode(&SPI0->CR, false);
-	ST7565_WriteByte(0x40);
-	for (unsigned line = 0; line < FRAME_LINES; line++) {
+	void ST7565_BlitLine(unsigned line)
+	{
+		SPI_ToggleMasterMode(&SPI0->CR, false);
+		ST7565_WriteByte(0x40);    // start line ?
 		DrawLine(0, line+1, gFrameBuffer[line], LCD_WIDTH);
+		SPI_ToggleMasterMode(&SPI0->CR, true);
 	}
-	SPI_ToggleMasterMode(&SPI0->CR, true);
-}
-
-void ST7565_BlitLine(unsigned line)
-{
-	SPI_ToggleMasterMode(&SPI0->CR, false);
-	ST7565_WriteByte(0x40);    // start line ?
-	DrawLine(0, line+1, gFrameBuffer[line], LCD_WIDTH);
-	SPI_ToggleMasterMode(&SPI0->CR, true);
-}
-
-void ST7565_BlitStatusLine(void)
-{	// the top small text line on the display
-	SPI_ToggleMasterMode(&SPI0->CR, false);
-	ST7565_WriteByte(0x40);    // start line ?
-	DrawLine(0, 0, gStatusLine, LCD_WIDTH);
-	SPI_ToggleMasterMode(&SPI0->CR, true);
-}
-*/
-
 
+	void ST7565_BlitStatusLine(void)
+	{	// the top small text line on the display
+		SPI_ToggleMasterMode(&SPI0->CR, false);
+		ST7565_WriteByte(0x40);    // start line ?
+		DrawLine(0, 0, gStatusLine, LCD_WIDTH);
+		SPI_ToggleMasterMode(&SPI0->CR, true);
+	}
+#endif
 
 void ST7565_FillScreen(uint8_t value)
 {