Si4020
3
PACKAGE PIN DEFINITIONS, MICROCONTROLLER MODE
Pin type key: D=digital, A=analog, S=supply, I=input, O=output, IO=input/output
Microcontroller Mode Pin Assignment
Pin
Name
Type
Function
1
SDI
DI
Data input of serial control interface
2
SCK
DI
Clock input of serial control interface
3
nSEL
DI
Chip select input of serial control interface (active low)
4
PB1
DI
Push-button input #1 (active low with internal pull-up resistor)
5
PB2
DI
Push-button input #2 (active low with internal pull-up resistor)
6
PB3
DI
Push-button input #3 (active low with internal pull-up resistor)
7
PB4
DI
Push-button input #4 (active low with internal pull-up resistor)
8
CLK
DO
Microcontroller clock (1 MHz-10 MHz)
9
XTL
AIO
Crystal connection (other terminal of crystal to VSS)
10
VSS
S
Ground reference
11
MOD
DI
Connect to logic high (microcontroller mode)
12
RFN
AO
Power amplifier output (open collector)
13
RFP
AO
Power amplifier output (open collector)
14
nIRQ
DO
Interrupt request output for microcontroller (active low) and status read output
15
VDD
S
Positive supply voltage
16
FSK
DI
Serial data input for FSK modulation