st7920_graphics.c

一个测试LCD的应用程序

// Wait and Clear
void WAC(void)
{
	DelayMs(1000);
	gTile(0x00, 0x00);
}

// Read data from GDRAM
uint16 ReadData(uint8 xUnit, yBit)
{
	uint16 dByte;
	Locate(xUnit, yBit);
	LCD_DataPort = 0xFF;
	LCD_RS = iDat;
	LCD_RW = 1;
	// A Dummy Read
	LCD_E = 1;
	LCD_E = 0;
	// Read Higher Byte
	LCD_E = 1;
	DelayUs(80);
	dByte = LCD_DataPort;	
	dByte <<= 8;
	LCD_E = 0;
	// Read Lower Byte
	LCD_E = 1;
	DelayUs(80);
	dByte |= LCD_DataPort;	
	LCD_E = 0;
	LCD_DataPort = 0xFF;
	return dByte;
}
// Locate a position in Gaphic Mode
void Locate(uint8 xUnit, yBit)
{
	// 1xUnit = 16 dots, 1yBit = 1 dot
	SetMode(LCD_GMODE);
	SendByte(iCmd, 0x80 + yBit);
	SendByte(iCmd, 0x80 + xUnit);
}

// Tile LCD screen with two datas in Gaphic Mode
void gTile(uint8 fst, snd)
{
	uint8 i, k;
	for (i = 0; i < LCD_YMAX; i++)
	{
		Locate(0, i);
		for (k = 0; k < LCD_XMAX; k++)
		{
			SendByte(iDat, fst);
			SendByte(iDat, snd);
		}
	}
}

// Draw a Horizontal Line with special style
void LineHs(uint8 X0, Y0, xUnits, Style)
{
	uint8 i;
	Locate(X0, Y0);
	for (i = 0; i < xUnits; i++)
	{
		SendByte(iDat, Style);
		SendByte(iDat, Style);
	}
}

// Draw a Horizontal Line
void LineH(uint8 X0, Y0, xDots)
{
	uint8 i;
	uint8 xUnit;
	uint16 OldData;
	uint16 NewData;
	
	for (i = 0; i < xDots; i++)
	{
		xUnit = (i + X0)/16;
		OldData = ReadData(xUnit, Y0);
		NewData = OldData|(0x0001 << (15 - i%16));
		
		Locate(xUnit, Y0);
		SendByte(iDat, NewData >> 8);
		SendByte(iDat, NewData & 0x00FF);
	}
}


// Draw a Vertical Line
void LineV(uint8 X0, Y0, yBits)
{
	uint8 i;
	uint8 xUnit = X0/16;
	uint16 OldData;
	uint16 NewData;	
	
	for (i = 0; i < yBits; i++)
	{
		OldData = ReadData(xUnit, Y0 + i);
		NewData = OldData|(0x0001 << (15 - X0%16));
		
		Locate(xUnit, Y0 + i);
		SendByte(iDat, NewData >> 8);
		SendByte(iDat, NewData & 0x00FF);
	}
}

// Display Standard Testing Graphics
void GraphicTest(void)
{
	uint8 i, k;
	uint8 code TestData[][2] =
	{
		{0xFF,0xFF},// All
		{0x00,0x00},// None		
		{0xAA,0xAA},// Virtical 1
		{0x55,0x55},// Virtical 2
		{0xFF,0x00},// Horizontal 1
		{0x00,0xFF},// Horizontal 2
		{0xAA,0x55},// Stars 1
		{0x55,0xAA} // Stars 2
	};
	
	for (i = 0; i < 4; i++)
	{
		gTile(TestData[i][0], TestData[i][1]);
		WAC();
	}
	
	for (k = 4; k < 8; k++)
	{
		for (i = 0; i < 32; i += 2)
		{
			LineHs(0, i, LCD_XMAX, TestData[k][0]);
			LineHs(0, i + 1, LCD_XMAX, TestData[k][1]);
		}
		WAC();
	}
	
	// Fullscreen Rectangle
	LineH(0, 0, LCD_CMAX);
	LineH(0, LCD_YMAX - 1, LCD_CMAX);
	LineV(0, 0, LCD_YMAX);
	LineV(LCD_CMAX - 1, 0, LCD_YMAX);
	WAC();
}