KEYBOARD STATES
These states of operation refer only
to the keyboard functionality and,
although they are related to power
states, they are also independent of
them.
"Send All Keys"
Entry Conditions: Power on reset,
soft reset, PWR_OK =1,
{(LID=1) AND (WUKO=0)}
Exit Conditions: PWR_OK = 0 ->
"Send No Keys"(WUKO=1) AND
(Key Press) -> "Send Wake-Up
Keys Only"(LID = 0) AND
(WUKO=0) AND (Key Press) ->
"Send XSW Key Only"
Description: This is the UR5HCSPI-
06’s normal state of operation,
accepting and transmitting every
key press to the system. This state
is entered after the power-on and is
sustained while the unit is being
used.
“Send Wake-Up Keys Only”
Entry Conditions: (WUKO=1) AND
(Key or Switch press)
Exit Conditions: Soft Reset -> “Send
All Keys”PWR_OK = 0 -> “Send No
Keys”
Description: This state is entered
when the user turns the unit off. A
signal line driven by the host will
notify the UR5HCSPI-06 about this
state transition. While in this state,
the UR5HCSPI-06 will transmit only
keys programmed to be wake-up
keys to the system. It is not
necessary for the UR5HCSPI-06 to
detect this transition in real time,
since it does not affect any
operation besides buffering
keystrokes.
(LID = 0) AND (WUK0=0)
Send
XSW Key
Only
AND Key Press
Send All
(LID = 1) AND (WUKO=0) Keys
AND Key Press
WUKO=1
AND Key Press
WUKO =1
AND Key
Press
Soft Reset
(PWR_OK =1)
AND (LID = 0)
AND (WUKO=0)
AND Key Press
PWR_OK ↓
PWR_OK ↓
(PWR_OK =1)
AND (WUKO=0)
AND (LID=1)
AND Key Press
PWR_OK = 0
Send Wake
Up Keys
Only
PWR_OK ↓
(PWR_OK =1) AND Key Press
AND (WUKO = 1)
Send
No Keys
Figure 2: The UR5HCSPI-06 implements four modes of keyboard and switch operation.
“Send No Keys"
Entry Conditions: PWR_OK
transition from high to low
Exit Conditions: (PWR_OK = 1)
AND (Matrix key pressed OR
Switch OR _WKUP)
3. While in this state all interrupts
are disabled. The UR5HCSPI-06
will exit this state on the next
interrupt event that detects the
PWR_OK line has been de-
asserted.e
“Send XSW Key Only"
Description: This state is entered
when a PWR_OK signal is asserted
(transition high to low), indicating a
critically low level of battery
voltage. The PWR_OK signal will
cause an interrupt to the
UR5HCSPI-06, which guarantees
that the transition is performed in
real time. While in this state, the
UR5HCSPI-06 will perform as
follows:
1. The UR5HCSPI-06 will enter the
STOP mode for maximum energy
conservation.
2. Stop mode time-out entry will be
shortened to further conserve
energy.
Entry Condition: (LID=0) AND
(WUKO=0) AND (Key Press)
Exit Condition: (LID=1) AND
(WUKO=0) AND (Key Press) ->
“Send All Keys”PWR_OK = 0 ->
“Send No Keys”
(WUKO = 1) AND (Key Press) ->
“Send Wake Up Keys Only”
Description: This state is entered
upon closing the lid of the device.
While in this state, the encoder will
transmit only the XSW key, which is
located outside the unit. This
feature is designed to
accommodate buttons on the
outside of the box, such as a
microphone button, that need to be
used while the lid is closed.
Copyright Semtech 1997-2000
7
DOC5-SPI-06-DS-103
www.semtech.com