CC2510FX Datasheet, PDF (204/253 Pages) List of Unclassifed Manufacturers – True System-on-Chip with Low Power RF Transceiver and 8051 MCU

CC2510Fx / CC2511Fx
By setting the value to zero, the preamble
quality qualifier of the sync word is disabled.
A “Preamble Quality reached” flag can also be
observed in the status register bit
PKTSTATUS.PQT_REACHED. This flag asserts
when the received signal exceeds the PQT.
15.10.3 RSSI
The RSSI value is an estimate of the signal
level in the chosen channel. This value is
based on the current gain setting in the RX
chain and the measured signal level in the
channel.
In RX mode, the RSSI value can be read
continuously from the RSSI status register.
The RSSI value is in dB with ½dB resolution.
The RSSI update rate depends on the receiver
filter bandwidth (BW_channel defined in Section
Error! Reference source not found.) and
AGCCTRL0.FILTER_LENGTH.
f _RSSI
= ^{2 ⋅ BWchannel}
8 ⋅ 2^{FILTER _ LENGTH}
If PKTCTRL1.APPEND_STATUS is enabled the
last RSSI value of the packet is automatically
added to the first byte appended after the
data.
The RSSI value read from the RSSI status
register is a 2’s complement number. The
following procedure can be used to convert the
RSSI reading to an absolute power level
(RSSI_dBm).
1) Read the RSSI status register
2) Convert the reading from a hexadecimal
number to a decimal number (RSSI_dec)
3) If RSSI_dec ≥ 128 then RSSI_dBm =
(RSSI_dec - 256)/2 – RSSI_offset
4) Else if RSSI_dec < 128 then RSSI_dBm =
(RSSI_dec)/2 – RSSI_offset
Error! Reference source not found.Table 63
gives typical values for the RSSI_offset. Figure
48 shows typical plots of RSSI reading as a
function of input power level for different data
rates.
Data rate
2.4 kbps
10 kbps
250 kbps
500 kbps
RSSI_offset (decimal)
71
69
72
72
Table 63: Typical RSSI_offset values
CC2510Fx/CC2511Fx PRELIMINARY Data Sheet (Rev. 1.2) SWRS055A Page 204 of 252