Technical data

USB and PS/2 Multimedia Keyboard Interface
USB and PS/2 Multimedia Keyboard Interface, Rev. 1
16 Freescale Semiconductor
1.5.8 Keyboard to Host Commands
Table 1-3. Keyboard to Host Commands
Code Description Implemented
$00 Keyboard detection or overrun error YES
$AA Basic assurance test passed YES
$EE Echo YES
$FA Acknowledge YES
$FE Resend YES
1.5.9 PS/2 Scan Codes
There are three sets of scan codes (code 1, 2, and 3). Most PCs support scan code set 2, hence this is
the only scan code the firmware supports. Make code or break code is sent when any key is pressed or
released. While a key is pressed, its make code is sent out repeatedly and the rate depends on the
typematic repeat value.
In addition to the IBM standard, Microsoft has published standards for the Windows keys, Power
Management keys (sleep, wake, and power), and the Audio Control keys.
Table 1-4. Scan codes supported by Windows 98, ME, and 2000
Description Make Code Break Code
Left Windows $E0, $1F $E0, $F0, $1F
Right Windows $E0, $27 $E0, $F0, $27
Applications $E0, $2F $E0, $F0, $2F
Power $E0, $37 $E0, $F0, $37
Sleep $E0, $3F $E0, $F0, $3F
Wake $E0, $5E $E0, $F0, $5E
Table 1-5. Scan codes supported by Windows ME and 2000
Description Make Code Break Code
Scan next track $E0, $4D $E0, $F0, $4D
Scan previous track $E0, $15 $E0, $F0, $15
Stop $E0, $3B $E0, $F0, $3B
Play/Pause $E0, $34 $E0, $F0, $34
Mute $E0, $23 $E0, $F0, $23
Volume increase $E0, $32 $E0, $F0, $32
Volume decrease $E0, $21 $E0, $F0, $21
AL Email Reader $E0, $48 $E0, $F0, $48
AC search $E0, $10 $E0, $F0, $10
AC Home $E0, $3A $E0, $F0, $3A
AC Forward $E0, $30 $E0, $F0, $30
AC Stop $E0, $28 $E0, $F0, $28
AC Refresh $E0, $20 $E0, $F0, $20
AC Bookmarks $E0, $18 $E0, $F0, $18