ST25R3918 datasheet(59/141 Pages) STMICROELECTRONICS

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DS13490 Rev 2

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ST25R3918

Application information

140

4.4.12

Clear RSSI

The receiver automatically clears the RSSI bits in the RSSI display register and starts a new

measurement of the RSSI when a new reception is started (e.g. after a Transmit direct

command). Since the RSSI bits store the peak value (peak-hold type) eventual variation of

the receiver input signal will not be followed (this may happen in case of a long message or

test procedure).

The direct command Clear RSSI clears the RSSI bits in the RSSI display register, and

restarts the RSSI measurement. This allows to obtain multiple RSSI measurements during a

single reception.

4.4.13

Transparent mode

This command sets the receiver and transmitter into the transparent mode. The device

enters the transparent mode on the rising edge of the BSS signal of the SPI frame used to

send the direct command. The transparent mode is maintained as long as signal BSS is

kept high, that is, the following SPI command sent from the microcontroller will automatically

stop the transparent mode.

4.4.14

Measure power supply

This command measures the power supply. The bits mpsv<2:0> in the Regulator voltage

control register select which signal is measured. The result of the measurement is stored in

the A/D converter output register.

For power supply measurements the selected supply input voltage is divided by three and

measured with the A/D converter in absolute mode. This leads to a resolution of 23.4 mV

per LSB for all power supply measurements.

Duration time: 25 μs max.

ST25R3918 Datasheet(PDF) 59 Page - STMicroelectronics