SPIRIT1 datasheet(65/94 Pages) STMICROELECTRONICS

65 / 94 page

SPIRIT1

Transmission and reception

Doc ID 022758 Rev 3

65/94

The algorithm is controlled by the following parameters:

●

AS_MEAS_TIME: this parameter controls the time interval for RSSI measurement

(ANT_SELECT_CONF register, allowed values 0...7). The actual measurement time is:

Equation 11

●

AS_ENABLE: this parameter enables the antenna switching function

(ANT_SELECT_CONF register: 0: disabled; 1: enabled).

9.12

Frequency hopping

In order to ensure good link reliability in an interference corrupted scenario, the device

supports frequency hopping, managed by the MCU; in particular, the SPIRIT1 supports

slow frequency hopping, meaning that the systems change frequency at a rate slower than

the information rate.

Depending on the desired blanking interval (the time during a hop), frequency hopping can

be done by performing the complete PLL calibration for each channel hop, or reading in the

suitable register calibration data calculated at startup and stored in the non-volatile memory

of the MCU. The former solution gives a long blanking interval but is more robust compared

with supply voltage and temperature variation. The latter provides a shorter blanking time

but is sensitive to voltage and temperature variation and requires memory space to store

calibration data for each channel involved in hopping.

meas

CHFLT_E

AS_meas_time

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SPIRIT1 Datasheet(PDF) 65 Page - STMicroelectronics