//pin腳定義
//SD卡使用SPI模式進行讀寫
//CS  ->P2.2
//MOSI->P2.3
//CLK ->P2.4
//MISO->P2.6

sbit CS =P2^2;
sbit SI =P2^3;
sbit SCK=P2^4;
sbit SO =P2^6;

#define CS_SD_EN    (CS=0)      //為低時表示片選
#define CS_SD_DIS   (CS=1)      //disable     
#define SCK_SD_LOW  (SCK=0)     //low
#define SCK_SD_HIGH (SCK=1)     // SCK = 1
#define SI_SD_LOW   (SI=0)      //(SI,SO均相對SSD)
#define SI_SD_HIGH  (SI=1)      //SI=1