首先了解TFT LCD的時(shí)序,每個(gè)VSYNC信號(hào)表示一幀數(shù)據(jù)的開始,每個(gè)HSYNC表示一行數(shù)據(jù)的開始,無論這些數(shù)據(jù)是否有效,每個(gè)VCLK表示正在傳輸一個(gè)像素的數(shù)據(jù),無論它是否有效。VSPW稱為垂直同步信號(hào)的脈寬,VBPD稱為垂直同步信號(hào)的后肩,VFPD稱為垂直同步信號(hào)的前肩。HSPW稱為水平同步信號(hào)的脈寬,HBPD稱為水平同步信號(hào)的后肩,HFPD稱為水平同步信號(hào)的前肩。查看時(shí)序圖,VSYNC信號(hào)有效時(shí),表示一幀數(shù)據(jù)的開始,VSPW表示VSYNC信號(hào)的脈沖寬度為(VSPW+1)個(gè)HSYNC信號(hào)周期,即(VSYNC+1)行,這(VSPW+1)行的數(shù)據(jù)無效。VSYNC信號(hào)脈沖之后,還要經(jīng)過(VBPD+1)個(gè)HSYNC信號(hào)周期,有效的行數(shù)據(jù)才出現(xiàn)。所以,在VSYNC信號(hào)之后,總共還要經(jīng)過(VSPW+1+VBPD+1)個(gè)無效行,第一個(gè)有效的行才會(huì)出現(xiàn)。隨后即發(fā)出(LINEVAL+1)行的有效數(shù)據(jù),隨后是(VFPD+1)個(gè)無效行。HSYNC的類似。不過是以VCLK信號(hào)周期為單位。然后主要就是配置5個(gè)LCD控制寄存器,3個(gè)幀緩沖區(qū)起始地址寄存器。注意HSYNC和VSYNC信號(hào),CPU發(fā)出的是正脈沖,LCD需要的是負(fù)的,所以極性取反,INVVLINE和INVVFRAME置1。M5D宏是用來取低21位。有一些右移一位的操作,主要是進(jìn)行字節(jié)和半字地址的轉(zhuǎn)換。LCD中需要的半字地址,幀緩沖區(qū)最低位是A[1]。BSWP和HWSWP是字節(jié)和半字交換,主要是處理大小端問題,如果輸出的漢字反了,置這個(gè)位為1。volatile U32 LCD_BUFFER[240][320];這個(gè)是設(shè)的幀緩沖區(qū),即視口,是幀內(nèi)存的一部分,這個(gè)程序中,幀內(nèi)存和幀緩沖區(qū)一樣大。幀內(nèi)存在SDRAM中,相當(dāng)于顯存。只要向幀緩沖區(qū)中寫入數(shù)據(jù),LCD的DMA控制器會(huì)自動(dòng)將數(shù)據(jù)從總線發(fā)到LCD驅(qū)動(dòng)器。在VCLK的上升沿發(fā)送數(shù)據(jù),在VCLK的下降沿,LCD驅(qū)動(dòng)器接受數(shù)據(jù)。BPP24BL是設(shè)置LCD的顯示模式為24BPP時(shí),一個(gè)4字節(jié)中哪3個(gè)字節(jié)有效。PAGESIZE是幀緩沖區(qū)的水平寬度,OFFSET是一行剩下的長(zhǎng)度。VD[23]"VD[0],是24根數(shù)據(jù)線,即RGB信號(hào)線。
下面的程序?qū)CD涂成紅色,然后畫一個(gè)藍(lán)色的矩形。
#define rGPCCON? ? (*(volatile unsigned *)0x56000020)??
#define rGPCUP? ???(*(volatile unsigned *)0x56000028)??
#define rGPDCON? ? (*(volatile unsigned *)0x56000030)??
#define rGPDUP? ???(*(volatile unsigned *)0x56000038)??
#define rLCDCON1? ? (*(volatile unsigned *)0x4d000000)? ?
#define rLCDCON2? ? (*(volatile unsigned *)0x4d000004)? ?
#define rLCDCON3? ? (*(volatile unsigned *)0x4d000008)? ?
#define rLCDCON4? ? (*(volatile unsigned *)0x4d00000c)? ?
#define rLCDCON5? ? (*(volatile unsigned *)0x4d000010)? ?
#define rLCDSADDR1??(*(volatile unsigned *)0x4d000014)? ?
#define rLCDSADDR2??(*(volatile unsigned *)0x4d000018)??
#define rLCDSADDR3??(*(volatile unsigned *)0x4d00001c)??
#define rLCDINTMSK??(*(volatile unsigned *)0x4d00005c)??
#define rTPAL? ?? ? (*(volatile unsigned *)0x4d000050)??
#define rGPGCON? ? (*(volatile unsigned *)0x56000060)? ?//Port G control??
#define rGPGDAT? ? (*(volatile unsigned *)0x56000064)? ?//Port G data??
#define rGPGUP? ???(*(volatile unsigned *)0x56000068)? ?//Pull-up control G??
#define rLCDINTMSK??(*(volatile unsigned *)0x4d00005c)??
#define rTPAL? ?? ? (*(volatile unsigned *)0x4d000050)??
#define rTCONSEL? ???(*(volatile unsigned *)0x4d000060)? ?//LPC3600 Control --- edited by junon??
//垂直同步信號(hào)的脈寬、后肩和前肩??
#define VSPW? ?? ? 15??
#define VBPD? ?? ? 3??
#define VFPD? ?? ? 5??
//水平同步信號(hào)的脈寬、后肩和前肩??
#define HSPW? ?? ? 8??
#define HBPD? ?? ? 58??
#define HFPD? ?? ?15??
#define CLKVAL 10??
#define HOZVAL 319??
#define LINEVAL 239??
#define PWREN 1??
#define MMODE 0??
#define PNRMODE 3??
#define BPPMODE 13??
#define INVVCLK 0??
#define INVVD 0??
#define INVVDEN 0? ?
#define U32 unsigned int? ?
#define M5D(n) ((n) & 0x1fffff)??
#define PAGEWIDTH 320??
#define OFFSIZE 0??
#define LCD_XSIZE 320??
#define LCD_YSIZE 240??
#define SCR_XSIZE 320??
#define SCR_YSIZE 240??
#define INVVLINE??1? ?? ?
#define INVVFRAME 1? ?? ?
#define BPP24BL 0??
#define BSWP 0??
#define HWSWP 0??
volatile U32 LCD_BUFFER[240][320];??
void Init_LCD(){??
? ?? ???rLCDCON1=(CLKVAL<<8)|(MMODE<<7)|(PNRMODE<<5)|(BPPMODE<<1)|0;? ?//設(shè)置CLKVAL,VCLK=HCLK/[(CLKVAL+1)*2],決定VM的觸發(fā)方式,選擇顯示模式和BPP模式,暫時(shí)不要開啟LCD,因?yàn)檫€沒有設(shè)置好
? ?? ? rLCDCON2=(VBPD<<24)|(LINEVAL<<14)|(VFPD<<6)|(VSPW);? ? //rLCDCON2,rLCDCON3和rLCDCON4主要設(shè)置時(shí)序??
? ?? ? rLCDCON3=(HBPD<<19)|(HOZVAL<<8)|(HFPD);??
? ?? ? rLCDCON4=(HSPW);??
? ?? ? rLCDCON5 = (BPP24BL<<12) | (INVVCLK<<10) | (INVVLINE<<9) | (INVVFRAME<<8) | (0<<7) | (INVVDEN<<6) | (PWREN<<3)??|(BSWP<<1) | (HWSWP);??????????????????????
?? //INVVLINE和INVVFRAME需要進(jìn)行翻轉(zhuǎn),因?yàn)镃PU發(fā)出的是正脈沖,LCD使用的是負(fù)脈沖,所以要改變極性,PWREN使能電源信號(hào)
? ?? ? rLCDSADDR1=(((U32)LCD_BUFFER>>22)<<21)|M5D((U32)LCD_BUFFER>>1);??
? ?? ? rLCDSADDR2=M5D(((U32)LCD_BUFFER+(SCR_XSIZE*SCR_YSIZE*4))>>1 );??
? ?? ? rLCDSADDR3=PAGEWIDTH*32/16;??
? ?? ? rLCDINTMSK|=(3);? ?? ???
? ?? ? rTCONSEL = 0;? ?? ?? ?? ?
? ?? ? rGPCUP = 0x0;??
? ?? ? rGPDCON = 0xaaaaaaaa;??
? ?? ? rGPCCON = 0xaaaa02a9;??
? ?? ? rGPDUP = 0x0;??
? ?? ? rGPGUP=rGPGUP&("(1<<4))|(1<<4);? ?? ???
? ?? ? rGPGCON=rGPGCON&("(3<<8))|(3<<8);? ?
? ?? ? rLCDCON1 |= 1;? ?//使能數(shù)據(jù)輸出和LCD控制信號(hào)
}
void Paint_background(U32 c){??
? ? unsigned int i, j;??
? ? for(j = 0; j < LCD_YSIZE; j++)??
? ?? ???for(i = 0; i < LCD_XSIZE; i++)??
? ?? ?? ?? ?LCD_BUFFER[j][ i] = c;??
}??
void Paint_rectangle(U32 c){??
? ?? ???int i, j;??
? ?? ???for(i = 100; i < 200; i++)??
? ?? ?? ?? ?for(j = 100; j < 200; j++)??
? ?? ?? ?? ?? ? LCD_BUFFER[ i][j] = c;??
}??
int LcdMain(){??
? ? Init_LCD();??
? ? Paint_background(0xCD5C5C);??
? ? Paint_rectangle(0x000080);??
? ? while(1);??
}
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