w83977atf Winbond Electronics Corp America, w83977atf Datasheet - Page 168

• Manufacturer Part Number: w83977atf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

Exit the extended function mode
To exit the extended function mode, one write of 0xAA to EFER is required. Once the chip exits the
extended function mode, it is in the normal running mode and is ready to enter the configuration
mode.
Software programming example
The following example is written in Intel 8086 assembly language. It assumes that the EFER is
located at 3F0h, so EFIR is located at 3F0h and EFDR is located at 3F1h. If HEFRAS (CR26 bit 6) is
set, 3F0h can be directly replaced by 370h and 3F1h replaced by 371h.
;-----------------------------------------------------------------------------------
; Enter the extended function mode ,interruptible double-write
;-----------------------------------------------------------------------------------
MOV DX,3F0H
MOV AL,87H
OUT DX,AL
OUT DX,AL
;-----------------------------------------------------------------------------
; Configurate logical device 1, configuration register CRF0 |
;-----------------------------------------------------------------------------
MOV DX,3F0H
MOV AL,07H
OUT DX,AL
MOV DX,3F1H
MOV AL,01H
OUT DX,AL
;
MOV DX,3F0H
MOV AL,F0H
OUT DX,AL
MOV DX,3F1H
MOV AL,3CH
OUT DX,AL
;------------------------------------------
; Exit extended function mode
;------------------------------------------
MOV DX,3F0H
MOV AL,AAH
OUT DX,AL
; point to Logical Device Number Reg.
; select logical device 1
; select CRF0
; update CRF0 with value 3CH
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Publication Release Date:April 1998
W83977ATF
PRELIMINARY
Revision 0.53