SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 286

• Manufacturer Part Number: SCH3112I-NE
• Description: LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
• Manufacturer: SMSC [SMSC Corporation]

Rev 0.2 (09-28-04)
;----------------------------.
; ENTER CONFIGURATION MODE
;----------------------------‘
MOV DX,02EH
MOV AX,055H
OUT DX,AL
;----------------------------.
; CONFIGURE REGISTER CRE0,
Note 25.1 The configuration port base address can be relocated through CR26 and CR27.
Entering the Configuration State
The device enters the Configuration State when the following Config Key is successfully written to the
CONFIG PORT.
Config Key = <0x55>
Exiting the Configuration State
The device exits the Configuration State when the following Config Key is successfully written to the
CONFIG PORT.
Config Key = <0xAA>
CONFIGURATION SEQUENCE
To program the configuration registers, the following sequence must be followed:
1. Enter Configuration Mode
2. Configure the Configuration Registers
3. Exit Configuration Mode.
Enter Configuration Mode
To place the chip into the Configuration State the Config Key is sent to the chip’s CONFIG PORT. The
config key consists of 0x55 written to the CONFIG PORT. Once the configuration key is received
correctly the chip enters into the Configuration State (The auto Config ports are enabled).
Configuration Mode
The system sets the logical device information and activates desired logical devices through the INDEX
and DATA ports. In configuration mode, the INDEX PORT is located at the CONFIG PORT address
and the DATA PORT is at INDEX PORT address + 1.
The desired configuration registers are accessed in two steps:
1. Write the index of the Logical Device Number Configuration Register (i.e., 0x07) to the INDEX
2. Write the address of the desired configuration register within the logical device to the INDEX PORT
Note: If accessing the Global Configuration Registers, step (a) is not required.
Exit Configuration Mode
To exit the Configuration State the system writes 0xAA to the CONFIG PORT. The chip returns to the
RUN State.
Note: Only two states are defined (Run and Configuration). In the Run State the chip will always be
Programming Example
The following is an example of a configuration program in Intel 8086 assembly language.
PORT and then write the number of the desired logical device to the DATA PORT
and then write or read the configuration register through the DATA PORT.
ready to enter the Configuration State.
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DATASHEET
LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
270
SMSC SCH311X
Datasheet