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Si4421
Control Commands
Control Command Related Parameters/Functions Related control bits
1 Configuration Setting Command
Frequency band, crystal oscillator load capacitance,
RX FIFO and TX register enable
el, ef, b1 to b0, x3 to x0
2 Power Management Command
Receiver/Transmitter mode change, synthesizer,
crystal oscillator, PA, wake-up timer, clock output
enable
er, ebb, et, es, ex, eb, ew, dc
3 Frequency Setting Command Frequency of the local oscillator/carrier signal f11 to f0
4 Data Rate Command Bit rate cs, r6 to r0
5 Receiver Control Command
Function of pin 16, Valid Data Indicator, baseband
bandwidth, LNA gain, digital RSSI threshold
p16, d1 to d0, i2 to i0, g1 to g0, r2
to r0
6 Data Filter Command Data filter type, clock recovery parameters al, ml, s, f2 to f0
7 FIFO and Reset Mode Command
Data FIFO IT level, FIFO start control, FIFO enable
and FIFO fill enable, POR sensitivity
f3 to f0, sp, ff, al, dr
8 Synchron Pattern Command Synchron pattern b7 to b0
9 Receiver FIFO Read Command RX FIFO read
10 AFC Command AFC parameters a1 to a0, rl1 to rl0, st, fi, oe, en
11 TX Configuration Control Command Modulation parameters, output power mp, m3 to m0, p2 to p0
12 PLL Setting Command CLK out buffer speed, dithering, PLL bandwidth ob1 to ob0, ddit, dly, bw0
13 Transmitter Register Write Command TX data register write t7 to t0
14 Wake-Up Timer Command Wake-up time period r4 to r0, m7 to m0
15 Low Duty-Cycle Command Enable and set low duty-cycle mode d6 to d0, en
16
Low Battery Detector and
Microcontroller Clock Divider
Command
LBD voltage and microcontroller clock division ratio d2 to d0, v3 to v0
17 Status Read Command Status bit readout
In general, setting the given bit to one will activate the related function. In the following tables, the POR column shows the default
values of the command registers after power-on.
Control Register Default Values
Control Register Power-On Reset Value
1 Configuration Setting Command 8008h
2 Power Management Command 8208h
3 Frequency Setting Command A680h
4 Data Rate Command C623h
5 Receiver Control Command 9080h
6 Data Filter Command C22Ch
7 FIFO and Reset Mode Command CA80h
8 Synchron Pattern Command CED4h
9 Receiver FIFO Read Command B000h
10 AFC Command C4F7h
11 TX Configuration Control Command 9800h
12 PLL Setting Command CC77h
13 Transmitter Register Write Command B8AAh
14 Wake-Up Timer Command E196h
15 Low Duty-Cycle Command C80Eh
16 Low Battery Detector and Microcontroller Clock Divider Command C000h
17 Status Read Command 0000h
14