Si4020
Simultaneously Pressed Push-Button Detect by Microcontroller
Microcontroller mode
Vdd
POR
(internal)
Push button
input 1
Push button
input 2
nIRQ
SPI
POR
PB1
PB1
PB2
PB1
PB2
PB1
PB_nIRQdly*
Status rd
Status rd
Status rd
Status rd
Status rd
Status rd
Status rd
Note:
*PB_nIRQdly is equal with the
debounce time
Simplified Block Diagram of Push-Button 1–4 Inputs
Notice:
Only one EVENT is
serviced simultaneously
the others are pending.
POR, LBD, WAKE UP TIMER,
P. BUTTONS EVENT FLAGS
VDD
VDD
WEAK PULL-UP
ENABLE/DISABLE
EVENT FLAG
bc
D
Q
Push-button1,2,3
Digital glitch
filter
CLR
CLK
SLEEP Command *
CLR for P.B1,2
STAT. REG. READ Command **
COUNT/SINGLE
Internal
blocker signal
to
b1, b2, b3
Push-button1
and
Push-button2
p4
To Digital glitch filter for
Push-button4
Push-button1
Push-button2
Note:
* In EEprom mode
** In uC controlled mode
With internal weak pull-up
Push-button4
17
SILICON [ SILICON ]
