NCT6627UD Nuvoton Technology Corporation of America, NCT6627UD Datasheet - Page 149

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

Specifications of NCT6627UD

• Lead Free Status / Rohs Status: Supplier Unconfirmed

12.5 Hardware GATEA20/Keyboard Reset Control Logic
The KBC includes hardware control logic to speed-up GATEA20 and KBRESET. This control logic is controlled
by LD5-CRF0 as follows:
12.5.1
DEFAULT
NAME
BIT
5-3
BIT
7
6
2
1
COMMAND
KB Control Register (Logic Device 5, CR-F0)
C1h
C2h
D0h
D1h
D2h
D3h
D4h
FXh
E0h
KCLKS1.
KCLKS0.
RESERVED.
P92EN (Port 92 Enable).
1: Enables Port 92 to control GATEA20 and KBRESET.
0: Disables Port 92 functions.
HGA20 (Hardware GATEA 20).
KCLKS1
7
1
KCLKS0
Continuously puts the lower four bits of Port1 into the STATUS register
Continuously puts the upper four bits of Port1 into the STATUS register
Send Port 2 value to the system
Only set / reset GateA20 line based on system data bit 1
Send data back to the system as if it came from the Keyboard
Send data back to the system as if it came from Auxiliary Device
Output next received byte of data from system to Auxiliary Device
Reports the status of the test inputs
Pulse only RC (the reset line) low for 6μs if the Command byte is even
6
0
5
0
RESERVED
DESCRIPTION
4
0
Select the KBC clock rate.
Bits
7 6
0 0: Reserved
0 1: Reserved.
1 0: KBC clock input is 12 MHz.
1 1: Reserved.
FUNCTION
-140-
3
0
W83627UHG/NCT6627UD
P92EN
Publication Release Date: October 26, 2010
2
0
HGA20
1
0
HKBRST#
0
0
Revision 1.7