W83637HF Datasheet, PDF (105/149 Pages) Winbond – LPC I/O

W83637HF
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
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Publication Release Date: June 25, 2003
Revision 1.3