NO:
W90P710 Programming Guide
VERSION:
2.0
PAGE:
230
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed, distributed or reproduced without permission
from Winbond.
Table No.: 2005-W90P710-11-A
2. Send Reset Command (0xFF) to PS/2 device.
21.4.2 Send
Commands
The content of the command register is showed below.
Table 21-1 Command register PS2CMD
31
30
29
28
27
26
25
24
RESERVED
23
22
21
20
19
18
17
16
RESERVED
15
14
13
12
11
10
9
8
RESERVED
RAP_SHIF EnCMD
7
6
5
4
3
2
1
0
PS2CMD
To send a command, write the command code to field PS2CMD[7:0], then write 1 to bit
EnCMD to start the transmit. After the transmit complete, EnCMD is automatically cleared to 0
and an interrupt is generated. Below are some of the commands the host may send to the
keyboard.
Table 21-2 Command table
Command
Code
Description
ED
Set Status LED's - This command can be used to turn on and off the Num Lock, Caps Lock &
Scroll Lock LED's. After Sending ED, keyboard will reply with ACK (FA) and wait for another
byte which determines their Status. Bit 0 controls the Scroll Lock, Bit 1 the Num Lock and Bit 2
the Caps lock. Bits 3 to 7 are ignored.
EE
Echo - Upon sending a Echo command to the Keyboard, the keyboard should reply with a
Echo (EE)
F0
Set Scan Code Set. Upon Sending F0, keyboard will reply with ACK (FA) and wait for another
byte, 01-03 which determines the Scan Code Used. Sending 00 as the second byte will return
the Scan Code Set currently in Use
F3
Set Typematic Repeat Rate. Keyboard will Acknowledge command with FA and wait for
second byte, which determines the Typematic Repeat Rate.
F4
Keyboard Enable - Clears the keyboards output buffer, enables Keyboard Scanning and
returns an Acknowledgment.
F5
Keyboard Disable - Resets the keyboard, disables Keyboard Scanning and returns an
Acknowledgment.
FE
Resend - Upon receipt of the resend command the keyboard will re- transmit the last byte sent.
