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AS3930

Data Sheet - D e t a i l e d D e s c r i p t i o n

The last 8 bits are the data that has to be written respectively read. A CS toggle high-low-high terminates the command mode.

If a direct command is sent (B15-B14=11) the bits from B13 to B9 defines the direct command while the last 8 bits are omitted. The Table 12

shows all possible direct commands:

All direct commands are explained below:

- clear_wake: clears the wake state of the chip. In case the chip has woken up (WAKE pin is high) the chip is set back to listening mode

- reset_RSSI: resets the RSSI measurement.

- trim_osc: starts the trimming procedure of the internal RC oscillator (see Figure 21)

- clear_false: resets the false wakeup register (R13=00)

- preset_default: sets all register in the default mode, as shown in Figure 7

Note:

In order to get the AS3930 work properly after sending the preset_default direct command, it is mandatory to write the R0<3:2>=00

Writing of Data to Addressable Registers (WRITE Mode)

The SDI is sampled at the falling edge of CLK (as shown in the following diagrams).

A CS toggling high-low-high indicates the end of the WRITE command after register has been written. The following example shows a write

command.

000

100

R4

000

101

R5

000

110

R6

000

111

R7

001

000

R8

001

001

R9

001

010

R10

001

011

R11

001

100

R12

001

101

R13

Table 12. List of Direct Commands

COMMAND_MODE

B13

B12

B11

B10

B9

B8

clear_wake

0

00000

reset_RSSI

0

00001

trim_osc

0

00010

clear_false

0

00011

preset_default

0

00100

Table 11. SDI Command Structure

B13

B12

B11

B10

B9

B8

Read/Write register