NCT6627UD Nuvoton Technology Corporation of America, NCT6627UD Datasheet - Page 34

• Manufacturer Part Number: NCT6627UD
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of NCT6627UD

• Lead Free Status / Rohs Status: Supplier Unconfirmed

The chip selects the Logical Device and activates the desired Logical Devices through Extended Function Index
Register (EFIR) and Extended Function Data Register (EFDR). The EFIR is located at the same address as the
EFER, and the EFDR is located at address (EFIR+1).
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 the EFDR.
To exit the Extended Function Mode, writing 0xAA to the 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.
The following example is written in Intel 8086 assembly language. It assumes that the EFER is located at 2Eh, so
the EFIR is located at 2Eh and the EFDR is located at 2Fh. If the HEFRAS (CR26 bit 6) is set, 2Eh can be directly
replaced by 4Eh and 2Fh replaced by 4Fh.
;-----------------------------------------------------
; Enter the Extended Function Mode
;-----------------------------------------------------
MOV
MOV
OUT
OUT
;-----------------------------------------------------------------------------
; Configure Logical Device 1, Configuration Register CRF0
;-----------------------------------------------------------------------------
MOV
MOV
OUT
MOV
MOV
OUT
;
6.1.2 Configure the Configuration Registers
6.1.3 Exit the Extended Function Mode
6.1.4 Software Programming Example
DX, 2EH
AL, 87H
DX, AL
DX, AL
DX, 2EH
AL, 07H
DX, AL
DX, 2FH
AL, 01H
DX, AL
; point to Logical Device Number Reg.
; select Logical Device 1
-25-
W83627UHG/NCT6627UD
Publication Release Date: October 26, 2010
Revision 1.7