XR18W753 Datasheet, PDF (18/27 Pages) Exar Corporation – SINGLE CHIP 868MHZ TO 956MHZ RF TRANSCEIVER

XR18W753
SINGLE CHIP 868MHZ TO 956MHZ RF TRANSCEIVER
3.2 DETAILED REGISTERS DESCRIPTIONS
REV. 1.0.0
ADDRESS
REGISTER NAME
DESCRIPTION
TYPE
0x27
AGC_ACT_VALUE
AGC setting instantaneous value
R
b[3:0] = 0000 --> IF-AGC set to 0dB
b[3:0] = 0001 --> IF-AGC set to -6dB
b[3:0] = 0010 --> IF-AGC set to -12dB
b[3:0] = 0011 --> IF-AGC set to -18dB
b[3:0] = 0100 --> IF-AGC set to -24dB
b[3:0] = 0101 --> IF-AGC set to -30dB
b[3:0] = 0110 --> IF-AGC set to -36dB
b[3:0] = 0111 --> IF-AGC set to -42dB
b[3:0] = 1000 --> IF-AGC set to -48dB
b[3:0] = 1001 --> not used
b[3:0] = 1010 --> not used
b[3:0] = 1011 --> not used
b[3:0] = 1100 --> not used
b[3:0] = 1101 --> not used
b[3:0] = 1110 --> not used
b[3:0] = 1111 --> not used
b[7:4] not used
0x28
Reserved
-
-
0x29
SLICER_LEVEL
Frequency offset in a link can be read out via this register. The
R
value is interpreted as an 8-bit two’s complement value (-128 to
+127). The conversion from this value to frequency is given below.
For 902 - 928 MHz application, the frequency offset is:
f_offset = 1MHz x SLICER_LEVEL / 128
For 868 MHz application, the frequency offset is:
f_offset = 400 kHz x SLICER_LEVEL / 128
0x2A-0x2D Reserved
-
-
0x2E
ED_THRES
Energy detection threshold
R/W
In IEE802.15.4 specification, it has been defined how the result of
the ED measurement given in MODEM_ED (0x15) need to be
reported. The value of ED_THRES is used to align the receiver
with the IEE802.15.4 ED measurement specification.
0x2F - 0x30 RSSI_ACT_VALUE_0,1 Actual RSSI value_0, 1
R
0x31-0x4F Reserved
0x50
TEST_0
The instantaneous level to the digital demodulator can be read via
these two registers. The value is interpreted as a two’s comple-
ment number. Together with the information of AGC_ACT_VALUE
(0x27), the instantaneous RF level can be calculated.
-
-
This register is used for factory test modes. For normal operation,
R/W
initialize this register to 0xD1.
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