关于SIS 968中APC REG的读写问题
sis 968 datasheet ，page468说了2种存取APC reg的方法，但是其中的SB reg.48h不知道是指哪个寄存器？IO index access
Software would use 2 way to access the APC register
1.Software would set SB reg. 48h bit 6 to 1 to enable the APC bank. Use index/data port
with 70h/71h to read/write data. After access, reset the SB reg. 48h bit 6 to 0 to disable
the APC bank.
2.Software would set SB reg. 48h bit 1 to 0 to enable the new re-index. Use index/data
port with 78h/79h to read/write data.
如果指的是48hRTC control的话， 我将0x7f填进去后，为什么通过70H，71H访问的还是 Internal RTC 你确认访问的位置是Bus0:Device2:Function0的Reg48h吗？
请用下面这段代码来试试
reg:BYTE
mov ax,0b108h
mov bx,10h
mov di,48h
int 1ah
mov reg,cl ;get RTC Control Register
mov cl,reg
and cl,3fh
or cl,40h ;set APCREG_EN
mov ax,0b10bh
mov bx,10h
mov di,48h
int 1ah
//now can access the APC register
mov cl,reg
mov ax,0b10bh
mov bx,10h
mov di,48h
int 1ah ;Restore 应该没弄错啊
(1L <<31) + (0L << 16) + (2 << 11) + ( 0 << 8) + (0x48 & 0xfc) 问题已找到，原因是bios默认ACPI base registers在I/O SPACE（在角落里有这个设定），而我在MEMORY SPACE 中读的，所以只要改一下就OK了
ps.看来还是要仔细的看datasheet
[ 本帖最后由 jackey_gu 于 2008-7-21 16:13 编辑 ]
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