笙泉单片机的时钟怎么选择啊

只看该作者 · 2012-2-16 15:14

新申请的isp writer U2和几片ma86e104
参考DATAsheet设置成外部时钟
IFADRH = 0x00;
IFADRL = 0x40;
ISPCR |= 0x80;
IFMT = 0x04;
SCMD = 0x46;
nop();
SCMD = 0xb9;
IFD = 0x20;
IFMT = 0x00;
delay_ms(3);
ISPCR &= 0x7f;
SCMD = 0x00;

为什么时钟没变啊？  请求大侠指点

只看该作者 · 2012-2-16 16:10

有木有用过这个片片的？

只看该作者 · 2012-2-16 16:24

参考以下设置，

IFADRH = 0x00;
IFADRL = 0x40;
ISPCR |= 0x80;
IFMT = 0x04;
IFD = 0x30;       //enable XTAL
SCMD = 0x46;
SCMD = 0xb9;
delay_ms(53;       //delay 3ms for XTAL_OSC stable
IFADRH = 0x00;
IFADRL = 0x40;
IFMT = 0x04;
IFD = 0x31;    //OSCin= XTAL
SCMD = 0x46;
SCMD = 0xb9;

IFADRH = 0x00;
IFADRL = 0x40;
IFMT = 0x04;
IFD = 0x21;    // disable IHRCOE , disable RC-OSC
SCMD = 0x46;
SCMD = 0xb9;

ISPCR &= 0x7f;