//========================================================================
// 文件名: LCD_Driver_User_A.asm
// 作  者: kaka.IN Hisense
//			sn.kaka@yahoo.com 
// 日  期: 2007/03/11
// 描  述: 底層接口驅動基礎程序集（ASM語言版本）
//
// 參  考: 請參考具體顯示器的硬件描述說明書或者是DataSheet,并以此來編寫底
//			層接口驅動程序
// 版  本:
//      2007/03/11      First version    Mz Design
// 注  意: 該文件當中，主要是對四個重要的函數進行了ASM的重寫
//========================================================================
.DEFINE		P_IOA_Data				0x7000
.DEFINE		P_IOA_Buffer			0x7001
.DEFINE		P_IOA_Dir				0x7002
.DEFINE		P_IOA_Attrib			0x7003
.DEFINE		P_IOA_Latch				0x7004
.DEFINE		P_IOB_Data				0x7005
.DEFINE		P_IOB_Buffer			0x7006
.DEFINE		P_IOB_Dir				0x7007
.DEFINE		P_IOB_Attrib			0x7008
	
// Define for the port use by LCD Driver
.define LCD_EP				0x1000
.define LCD_RW				0x0800
.define LCD_AO				0x0400
.define LCD_RE				0x0200
.define LCD_CS				0x0100


.define LCD_CMD_Dir			P_IOA_Dir
.define LCD_CMD_Attrib		P_IOA_Attrib
.define LCD_CMD_Buffer		P_IOA_Buffer

.define LCD_Data_BUS_Out	P_IOA_Buffer
.define LCD_Data_BUS_In		P_IOA_Data
.define LCD_Data_BUS_Dir	P_IOA_Dir
.define LCD_Data_BUS_Attrib	P_IOA_Attrib

.define LCD_Data_BUS_Byte	0//1

.external _TimeDelay
.code
	

//========================================================================
// 函數: unsigned int LCD_StatusRead(void)
// 描述: 從LCD中的顯示緩沖RAM當中讀一個字節的顯示數據
// 參數: 無  
// 返回: 讀出的數據，低八位有效（byte）
// 備注: 
// 版本:
//      2007/01/09      First version
// 注意: 
//========================================================================
.public _LCD_StatusRead
_LCD_StatusRead:
	r3 = [LCD_Data_BUS_Dir]				//設置數據口為輸入
.if LCD_Data_BUS_Byte==1 
	r2 = r3&0x00ff
.else
	r2 = r3&0xff00
.endif
	[LCD_Data_BUS_Dir] = r2
	
	r2 = [LCD_CMD_Buffer]				//得到IOB口的狀態
	r2 &= ~(LCD_EP+LCD_CS+LCD_AO)		//EP CS to Low 20050613  Editby xinqiang					
//	[LCD_CMD_Buffer] = r2 				//EP Low
	r2 |= (LCD_RW)
	[LCD_CMD_Buffer] = r2				//AO Hight, RW Hight
//	nop
	r2 |= LCD_EP
	[LCD_CMD_Buffer] = r2				//產生EP高電平，
//	nop
	r2 &= ~LCD_EP					//EP to Low
	[LCD_CMD_Buffer] = r2
	r1 = [LCD_Data_BUS_In]
	r2 |= LCD_CS
	[LCD_CMD_Buffer] = r2
	
//	r2 = [LCD_Data_BUS_Dir]				//恢復數據口為輸出狀態
.if LCD_Data_BUS_Byte==1 
//	r2 = r2|0xff00
	r1 = r1 lsr 4
	r1 = r1 lsr 4
.else
//	r2 = r2|0x00ff
	r1 = r1&0x00ff
.endif
	[LCD_Data_BUS_Dir] = r3
	retf