
W83637HF
Publication Release Date: June 25, 2003
- 100 -
Revision 1.3
First, write the Logical Device Number (i.e., 0x07) to the EFIR and then write the number of the desired
logical device to the EFDR. If accessing the Chip(Global) Control Registers, this step is not required.
Secondly, write the address of the desired configuration register within the logical device to the EFIR
and then write (or read) the desired configuration register through EFDR.
8.1.2.3 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.
8.1.2.4 Software programming example
The following example is written in Intel 8086 assembly language. It assumes that the EFER is located
at 2Eh, so EFIR is located at 2Eh and EFDR is located at 2Fh. If HEFRAS (CR26 bit 6) is set, 4Eh can
be directly replaced by 4Eh and 2Fh replaced by 4Fh.
;-----------------------------------------------------------------------------------
; Enter the extended function mode ,interruptible double-write |
;-----------------------------------------------------------------------------------
MOV
DX,2EH
MOV AL,87H
OUT
DX,AL
OUT
DX,AL
;-----------------------------------------------------------------------------
; Configuration logical device 1, configuration register CRF0 |
;-----------------------------------------------------------------------------
MOV
DX,2EH
MOV
AL,07H
OUT
DX,AL
; point to Logical Device Number Reg.
MOV
DX,2FH
MOV
AL,01H
OUT
DX,AL
; select logical device 1
;
MOV
DX,2EH
MOV
AL,F0H
OUT
DX,AL
; select CRF0
MOV
DX,2FH
MOV AL,3CH
OUT
DX,AL
; update CRF0 with value 3CH
;------------------------------------------
; Exit extended function mode |
;------------------------------------------
MOV
DX,2EH
MOV AL,AAH
OUT
DX,AL