
W83977TF
PRELIMINARY
Publication Release Date: March 1998
- 67 -
Revision 0.62
6.4
Commands, continued
COMMAND
FUNCTION
A5h
Load Password
Load Password until a "0" is received from the system
Enable Password
Enable the checking of keystrokes for a match with the password
Disable Auxiliary Device Interface
Enable Auxiliary Device Interface
Interface Test
A6h
A7h
A8h
A9h
Self-test
Returns 055h if self test succeeds
Interface Test
BIT
04
03
02
01
00
BIT DEFINITION
No Error Detected
Auxiliary Device "Clock" line is stuck low
Auxiliary Device "Clock" line is stuck high
Auxiliary Device "Data" line is stuck low
Auxiliary Device "Data" line is stuck low
AAh
ABh
Disable Keyboard Interface
Enable Keyboard Interface
Read Input Port(P1) and send data to the system
Continuously puts the lower four bits of Port1 into STATUS register
Continuously puts the upper four bits of Port1 into STATUS register
Send Port2 value to the system
Only set/reset GateA20 line based on the system data bit 1
Send data back to the system as if it came from 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 6
μ
S if Command byte is even
BIT
04
03
02
01
00
BIT DEFINITION
No Error Detected
Keyboard "Clock" line is stuck low
Keyboard "Clock" line is stuck high
Keyboard "Data" line is stuck low
Keyboard "Data" line is stuck high
ADh
AEh
C0h
C1h
C2h
D0h
D1h
D2h
D3h
D4h
E0h
FXh