System Installation
RUBY-9712VG2A User’s Manual
3-11
How to access W83627THF CR?
In RUBY-9712VG2A, the EFER = 002Eh, and EFDR = 002Fh.
EFER and EFDR are 2 IO ports needed to access W83627THF CR.
EFER is the Index Port, EFDR is the Data Port.
CR index number needs to be written into EFER first,
Then the data will be read/written from/to EFDR.
To R/W W83627THF CR, it is needed to Enter/Enable Configuration Mode first.
When completing the programming, it is suggested to Exit/Disable Configuration
Mode.
Enter Configuration Mode: Write 87h to IO port EFER twice.
Exit Configuration Mode: Write AAh to IO port EFER.
3.7.3 Example
Define GPIO4 as output pin, and output “0” to this pin.
mov
dx,2eh
; Enter Configuration Mode
mov al,87h
out dx,al
jmp $+2
out dx,al
mov dx,2eh
mov
al,2Ah
; Read CR2A
out dx,al
mov dx,2fh
in al,dx
or al,0FCh
;
CR2A_Bit[7..2].P[1,1,1,1,1,1]
mov ah,al
mov dx,2eh
mov al,2Ah
out dx,al
mov dx,2fh
mov al,ah
out dx,al
