Exiting the Configuration State
To exit the configuration state, write one byte of AAH data to the CONFIG PORT. The FDC37N769 will automatically
deactivate the Configuration Access Ports following this procedure, at which point configuration register access
cannot occur until the configuration state is explicitly re-enabled.
Programming Example
The following is a configuration register programming example written in Intel 8086 assembly language.
;-----------------------------.
; ENTER CONFIGURATION STATE |
;-----------------------------‘
MOV
MOV
OUT
DX,3F0H
AX,055H
DX,AL
;-----------------------------.
; CONFIGURE REGISTERS CR0-CRx |
;-----------------------------‘
MOV
MOV
OUT
MOV
MOV
OUT
;
DX,3F0H
AL,00H
DX,AL
DX,3F1H
AL,3FH
DX,AL
;Point to CR0
;Update CR0
MOV
MOV
OUT
MOV
MOV
OUT
;
DX,3F0H
AL,01H
DX,AL
DX,3F1H
AL,9FH
DX,AL
;Point to CR1
;Update CR1
; Repeat for all CRx registers
;
;-----------------------------.
; EXIT CONFIGURATION STATE
|
;-----------------------------‘
MOV
MOV
OUT
DX,3F0H
AX,AAH
DX,AL
SMSC DS – FDC37N769
Page 96 of 137
Rev. 02-16-07
DATASHEET
SMSC [ SMSC CORPORATION ]
