General Description A-3
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General Description
Winbond has a WDT feature inside its W83627HF chip. There are many configuration
Registors (CR ) in the W83627HF. The following sequence must be followed for CR
programming:
1)
Enter the extended function mode.
2)
Configure the configuration registers.
3)
Exit the extended function mode.
For instance:
1)
Enter extended function mode.
MOV DX,3F0H
MOV AL,87H
CLI
; disable interrupt
OUT DX,AL
JMP $+2
OUT DX,AL
STI
; enable interrupt
2)
Configurate logical device 1, configuration register CRF0.
MOV DX,3F0H
MOV AL,07H
OUT DX,AL
; point to Logical Device Number Register
MOV DX,3F1H
MOV AL,01H
OUT DX,AL
; select logical device 1
;
MOV DX,3F0H
MOV AL,0F0H
OUT DX,AL
MOV DX,3F1H
MOV AL,3CH
OUT DX,AL
; update CRF0 with value 3Ch
