CY82C693UB Cypress Semiconductor Corporation., CY82C693UB Datasheet - Page 109

• Manufacturer Part Number: CY82C693UB
• Description: Hypercache Tm / Stand-alone Pci Peripheral Controller With Usb
• Manufacturer: Cypress Semiconductor Corporation.

System to Keyboard Command Set. These commands are written from the controller to the keyboard. The command should
be written to the Input Buffer (Port 60H). If data is required along with the command, the system must perform a subsequent dat a
write to I/O Port 60H.
Keyboard to System Command Set. These commands are written from the keyboard to the controller.
Command
EDH
EEH
F2H
F3H
F4H
F5H
F6H
FEH
FFH
Command
00H
83H
ABH
AAH
FCH
EEH
FAH
FEH
FFH
Description
Set/Reset Keyboard LED status indicators:
Num Lock, Caps Lock, and Scroll Lock LEDs, which are found on most keyboards, can be turned on or off
using this command. The system must first write the EDH command to I/O port 60H and get acknowledged.
Then the system must write port 60H with the following data:
Bits 7–3: 00000
Bit 2:
Bit 1:
Bit 0:
Echo Command:
This command can be used to test the keyboard. A present and working keyboard will echo EEH after it
receives this command.
Read keyboard ID bytes:
The keyboard will acknowledge the command and send the two keyboard ID bytes.
Set typematic rate and delay period:
This command is used to set the typematic rate (make codes/second when a key is pressed and held down)
and delay period (number of milliseconds after a key is pressed before typematic starts). INT 16H Function
03H sends the Set Rate command F3H to the keyboard controller followed by the delay and rate values.
Begin Operation:
This command causes the keyboard to clear its output buffer and begin scanning.
Reset and Disable:
This command causes the keyboard to reset to its power-on default and disables scanning.
Reset and Enable:
This command causes the keyboard to reset to its power-on default and enables scanning.
Resend:
If the system detects an error in the previous transmission, this command will cause the keyboard to send the
transmission again.
Self-test:
This command causes the keyboard to initiate its internal diagnostic self-test.
Description
Overrun character (For scan code sets 2 and 3):
When the keyboard exceeds buffer capacity, it places 00H at the bottom of the buffer. When 00H reaches the
top of the buffer, it is sent to the system.
Low Keyboard ID Byte:
The keyboard responds to the Read ID bytes command by first sending the low ID byte.
High Keyboard ID Byte:
The keyboard responds to the Read ID bytes command by first sending the low ID byte. Then it sends the high
ID byte.
Power-on Diagnostics Completed:
If the power-on diagnostic tests completed successfully (no error detected), this command is sent to the
system.
Power-on Diagnostics Failed:
If the power-on diagnostic tests detected an error, this command is sent to the system. The keyboard controller
will wait to be reset or receive some other command from the system.
Echo Response:
This is the keyboard’s response to the system’s echo command.
Acknowledge (ACK):
The keyboard will acknowledge any valid keyboard command that the system transmits with an ACK command.
Resend:
If the keyboard detects an error in the previous transmission, this command will be sent, requesting the system
to send the transmission again.
Overrun character (For scan code set 1):
When the keyboard exceeds buffer capacity, it places FFH at the bottom of the buffer. When FFH reaches the
top of the buffer, it is sent to the system.
Caps Lock (1 Turns LED on)
Num Lock (1 Turns LED on)
Scroll Lock (1 Turns LED on)
PRELIMINARY
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CY82C693UB