Rainbow Electronics W90N745CDG - Manual (Page 388)

W90N745CD/W90N745CDG
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PS2 Host Controller RX Scan Code Register (PS2_SCANCODE)
REGISTER ADDRESS R/W DESCRIPTION RESET VALUE
PS2SCANCODE 0xFFFF_9008 R/W PS2 Host RX Scan Code Register 0x0000_0000
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 RX_shift_key RX_release RX_extend
7 6 5 4 3 2 1 0
RX_SCAN_CODE
BITS DESCRIPTIONS
[31:11] RESERVED -
[10] RX_shift_key
This Receive Shift Key bit indicates that left or right shift key on
the keyboard is hold. This bit is read only and will clear by host
when the release shift key codes are received.
[9] RX_release
Receive Released Byte
When one key has been released, the keyboard will send F0
(hex) to inform Host controller. This bit indicates software that
Host controller receives release byte (F0). This bit is read only
and will update when host has received next data byte.
[8] RX_extend
Receive Extend Byte
A handful of the keys on keyboard are extended keys and thus
require two more scan code. These keys are preceded by an
E0 (hex). This bit indicates software that Host controller
receives extended byte (E0). This bit is read only and will
update when host has received next data byte.
[7:0] RX_SCAN_CODE
PS2 Host Controller Received Data Field
This field stores the original data content transmitted from
device. This filed is valid when RX_IRQ is asserted. Note that
host will not report “Extend” or “Release” scan code to this field
and not generate interrupt if they are received by host, i.e.
0xE0 and 0xF0. The case of the shift key codes will be
determined by the TRAP_SHIFT bit of PS2_CMD register.