SIS5595 Datasheet, PDF (60/216 Pages) List of Unclassifed Manufacturers – Pentium PCI System I/O Chipset

SiS5595 PCI System I/O Chipset
1 : Inactive ( default )
0 : Active
P21 GA20 – Gate 20 Control Signal
1 : Inactive ( default )
0 : Active
3.8.4 KEYBOARD INTERNAL BIOS COMMANDS ( I/O PORT 64H )
Command
Keyboard Mode
Keyboard PS/2 Mode
01 – 1F
20 (00)
21 – 3F
41 – 5F
60 (40)
61 – 7F
Read Internal RAM – The controller sends value of RAM to output buffer.
Read Keyboard Controller’s Command byte – The controller sends the
current Command Byte to its output buffer.
Read Internal RAM – The controller sends value of RAM to output buffer.
Write Internal RAM – The next byte of data written to I/O 60h is placed into
Internal RAM.
Write Keyboard Controller’s Command Byte – The next byte of data written
to I/O 60h is placed in the controller’s command byte.
BIT
BIT DEFINITIONS
0 _{1 – Enable Keyboard Output-Buffer-Full Interrupt}
The KBC would generate an interrupt when it places keyboard
data into its output buffer.
1 1 – Enable Mouse-Buffer-Full Interrupt
The KBC would generate an interrupt when it places mouse data
into its output buffer.
2 1 – The controller generates a System Flag.
The value written to this bit is placed in the system flag bit of the
controller’s status register.
3 1– Disable Keyboard lock Switch “KLOCK#” (Even when the
KLOCK# enable bit equals 1).
4 1 – Disable Keyboard.
Disable the Keyboard interface by driving the ‘keyboard clock’ line
low. Data won’t be sent or received.
5 1 – Disable Mouse.
Disable the Mouse interface by driving the ‘mouse clock’ line low.
Data won’t be sent or received.
6 _{1 – IBM Personal Computer Compatibility Mode.}
Convert the scan codes received from keyboard to IBM PC. This
includes converting a two-byte sequence to the one-bye IBM
Personal Computer format.
7 0 – Reserved.
Write Internal RAM – The next byte of data written to I/O 60h is placed into
Internal RAM.
Preliminary V2.0 Nov. 2, 1998
54 Silicon Integrated Systems Corporation