UR5HCSPI View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'UR5HCSPI' PDF : 20 Pages View PDF
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’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 about this
state transition. While in this state,
the UR5HCSPI will transmit only
keys programmed to be wake-up
keys to the system. It is not
necessary for the UR5HCSPI to
detect this transition in real time,
since it does not effect any
operation besides buffering
keystrokes.
(LID = 0) AND (WUK0=0)
Send
AND Key Press
XSW Key
Only
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 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)
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, which guarantees that
the transition is performed in real
time. While in this state, the
UR5HCSPI will perform as follows:
1. The LED will be turned off.
Nevertheless, its state is saved and
will be restored after exiting the
disabled state (change of
batteries).
2. The UR5HCSPI will enter the
STOP mode for maximum energy
conservation.
3. Stop mode time-out entry will be
shortened to further conserve
energy.
4. While in this state all interrupts
are disabled. The UR5HCSPI will
exit this state on the next interrupt
event that detects the PWR_OK line
has been de-asserted.e
“Send XSW Key Only"
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 1997-2001
7
DOC5-SPI-DS-117
www.semtech.com
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