Si4021
13
Control Commands
Control Command
Related Parameters/Functions
Related control bits
1     Configuration Setting Command
Frequency band, microcontroller clock output, crystal
load capacitance, frequency deviation
b1 to b0, d2 to d0, x3
to x0, ms, m2 to m0
2     Power Management Command
Crystal oscillator, synthesizer, power amplifier, low
battery detector, wake-up timer, clock output buffer
a1 a0, ex, es, ea, eb,
et, dc
3     Frequency Setting Command
Carrier frequency
f11 to f0
4     Data Rate Command
Bit rate
r7 to r0
5     Power Setting Command
Nominal output power, OOK mode
ook, p2 to p0
6     Low Battery Detector Command
Low battery threshold limit, transmit bit synchronizer,
wake-up timer calibration
dwc, ebs, t4 to t0
7     Sleep Command
Length of the clock tail after power down
s7 to s0
8     Push-Button Command
Push-button related functions
p4, d1 to d0, b4 to b1,
bc
9     Wake-Up Timer Command
Wake-up time period
r4 to r0, m7 to m0
10    Data Transmit Command
Data transmission
11    Status Register Command
Transmitter status read
12    PLL Setting and Reset Mode Command
PLL bandwidth, reset mode
bw1 to bw0, dr
Note: In the following tables the POR column shows the default values of the command registers after power-on.
1. Configuration Setting Command
bit     15     14     13     12     11     10
9
8
7
6
5
4
3
2
1
0
POR
1
0
0
b1     b0     d2     d1     d0     x3     x2     x1     x0     ms    m2    m1    m0
8080h
b1    b0
Frequency Band {MHz]
0
0
315
0
1
433
1
0
868
1
1
915
Clock Output
Frequency [MHz]
0
0
0
1
0
0
1
1.25
0
1
0
1.66
0
1
1
2
1
0
0
2.5
1
0
1
3.33
1
1
0
5
1
1
1
10
d2    d1    d0
x3    x2    x1    x0
Crystal Load Capacitance [pF]
0
0
0
0
8.5
0
0
0
1
9.0
0
0
1
0
9.5
0
0
1
1
10.0
1
1
1
0
15.5
1
1
1
1
16.0
&
The resulting output frequency can be calculated as:
f
out
= f
0
(-1)
SIGN
* (M + 1) * (30 kHz)
where:
f
0
is the channel center frequency (see the next command)
M is the three bit binary number <m2 : m0>
SIGN = (ms) XOR (FSK input)
Note:
?    Use M in a range from 0 to 6.