Technical data

SET NAK TO IN EP0
SET STALL TO EP0 OUT
(CONTROL TRANSFER
COMPLETED)
ALL DATA
SENT?
PREPARE FOR
NEXT DATA STAGE
IN EPO HANDLER
NO [DATA STAGE]
YES
STATUS STAGE ?
NO
YES
RETURN
PREPARE FOR
OUT STAGE
Firmware Description
USB and PS/2 Multimedia Keyboard Interface, Rev. 1
Freescale Semiconductor 21
Figure 1-15. . IN EPO HANDLER
USB Key Codes
The key codes or usage IDs for a basic 104 keyboard are defined in the USB HID Usage Tables. In
addition to the basic key codes, Microsoft has published standards for the Windows keys, Power
Management keys (sleep, wake, and power), and the audio control keys.
ACPI Power Management Control
Table 1-7. Consumer Page HID Controls in Windows ME and 2000
USAGE USAGE NAME DATA TYPE
$81 Power Relative
$82 Sleep Relative
$83 Wake Relative
Consumer Page Audio Control
Table 1-8. Consumer Page HID Controls in Windows ME and 2000
USAGE USAGE NAME USAGE TYPE DATA TYPE
$B5 Scan Next Track One Shot Control Relative
$B6 Scan Previous Track One Shot Control Relative
$B7 Stop One Shot Control Relative
$CD Play/Pause One Shot Control Relative
$E0 Volume Linear Control Relative
$E2 Mute On/Off Control Relative
$E3 Bass Linear Control Relative