Silan
Semiconductors
SC83053
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0 2001.11.8.
6
Command from the system
The system can send commands to the keyboard at any time. The keyboard needs to respond within 20
milliseconds, unless the system prevents keyboard output, when doing self test or executing a RESET.
The following are the keyboard input commands and the actions that keyboard needs to take.
Set /Reset Status indicators ( Hex ED )
- Responds ACK.
- Receives option byte.
- Responds ACK.
- Updates status indicators.
- Returns to previous scanning state.
Echo ( Hex EEH )
- Responds with EE hex.
- Returns to previous scanning state.
Invalid commands ( Hex EF and F1 )
- Returns a RESEND command.
- Returns to previous scanning state.
Select Alternate Scan Codes ( Hex F0 )
- Responds ACK.
- Clears output buffer.
- Sets the default typematic rate/delay.
- Clears last typematic key.
- Receives option byte.
- Responds ACK.
- Option byte =
01 : selects scan code set 1
02 : selects scan code set 2