w83977tf Winbond Electronics Corp America, w83977tf Datasheet - Page 75

• Manufacturer Part Number: w83977tf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

6.3 Status Register
The status register is an 8-bit read-only register at I/O address 64H (Default, PnP programmable I/O
address LD5-CR62 and LD5-CR63), that holds information about the status of the keyboard controller
and interface. It may be read at any time.
6.4
BIT
Commands
0
1
2
3
4
5
6
7
COMMAND
20h
60h
A4h
Output Buffer Full
Input Buffer Full
System Flag
Command/Data
Inhibit Switch
Auxiliary Device Output
Buffer
General Purpose Time-
out
Parity Error
BIT FUNCTION
Read Command Byte of Keyboard Controller
Write Command Byte of Keyboard Controller
Test Password
Returns 0Fah if Password is loaded
Returns 0F1h if Password is not loaded
BIT
7
6
5
4
3
2
1
0
Reserved
Disable Auxiliary Device
Disable Keyboard
Reserve
System Flag
Enable Auxiliary Interrupt
IBM Keyboard Translate Mode
Enable Keyboard Interrupt
0: Output buffer empty
1: Output buffer full
0: Input buffer empty
1: Input buffer full
This bit may be set to 0 or 1 by writing to the system flag
bit in the command byte of the keyboard controller. It
defaults to 0 after a power-on reset.
0: Data byte
1: Command byte
0: Keyboard is inhibited
1: Keyboard is not inhibited
0: Auxiliary device output buffer empty
1: Auxiliary device output buffer full
0: No time-out error
1: Time-out error
0: Odd parity
1: Even parity (error)
BIT DEFINITION
- 66 -
FUNCTION
DESCRIPTION
Publication Release Date: March 1998
W83977TF
PRELIMINARY
Revision 0.62