SDBC的特殊寄存器（可位尋址的定義方法）

用于52兼容MCUConst 變量和 Const 變量在編譯的時候運算完By 萬致遠,sdbc 定義可位尋址的數據類型Type SFR_BIT_ADim SFR_BIT_A As sfr 定義字節地址sfr,如果Type里有和Type名一樣的變量，則編譯器將把它當作默認變量比如說這個type里面有SFR_BIT_A，那么外部給這個類定位地址，事實上是給這個變量定位地址比如Dim P0 As SFR_BIT_A at &H80，那么P0=0就是相當于MOV #80H,0.然后設計如果需要數字變量名，需要在前面加$，但是如果在類外/類型外引用，則不需要，with語句也需要類似P0.0=1。With P0 .$0=1 End With一樣在type內的地址聲明將在編譯時被固定處理，類似聲明P0在0x80，那么$0~$7固定為0x80~0x87Dim $0 As sbit at &SFR_BIT_ADim $1 As sbit at &SFR_BIT_A+1Dim $2 As sbit at &SFR_BIT_A+2Dim $3 As sbit at &SFR_BIT_A+3Dim $4 As sbit at &SFR_BIT_A+4Dim $5 As sbit at &SFR_BIT_A+5Dim $6 As sbit at &SFR_BIT_A+6Dim $7 As sbit at &SFR_BIT_A+7End TypeIO口定義Dim P0 As SFR_BIT_A at &H80聲明P0在0x80位置Dim P1 As SFR_BIT_A at &H90聲明P1在0x90位置Dim P2 As SFR_BIT_A at &HA0聲明P2在0xA0位置Dim P3 As SFR_BIT_A at &HB0聲明P3在0xB0位置IO口定義結束