Texas Instruments 3138 155 232931 - Manual (Page 76)

CC2420
SWRS041B Page 76 of 89
AGCTST0 (0x24) - AGC Test Register 0
Bit Field Name Reset R/W Description
15:12 LNAMIX_HYST[3:0] 3 R/W Hysteresis on the switching between different RF front-end
gain modes, defined in 2 dB steps
11:6 LNAMIX_THR_H[5:0] 25 R/W Threshold for switching between medium and high RF front-
end gain mode, defined in 2 dB steps
5:0 LNAMIX_THR_L[5:0] 9 R/W Threshold for switching between low and medium RF front-end
gain mode, defined in 2 dB steps
AGCTST1 (0x25) - AGC Test Register 1
Bit Field Name Reset R/W Description
15 - 0 W0 Reserved, write as 0
14 AGC_BLANK_MODE 0 R/W Set the VGA blanking mode when switching out a gain stage
When VGA_GAIN_OE = 0:
0 : Blanking is performed when the AGC algorithm switches
out one or more 14dB gain stages.
1 : Blanking is never performed.
When VGA_GAIN_OE = 1:
Blanking is performed when AGC_BLANK_MODE=1
13 PEAKDET_CUR_BOOST 0 R/W Doubles the bias current in the peak-detectors in-between the
VGA stages when set.
12:11 AGC_SETTLE_WAIT[1:0] 1 R/W Timing for AGC to wait for analog gain to settle.
10:8 AGC_PEAK_DET_MODE
[2:0]
0 R/W Sets the AGC mode for use of the VGA peak detectors:
Bit 2 : Digital ADC peak detector enable / disable
Bit 1 : Analog fixed stages peak detector enable /
disable
Bit 0 : Analog variable gain stage peak detector enable /
disable
7:6 AGC_WIN_SIZE[1:0] 1 R/W Window size for the accumulate and dump function in the
AGC.
0 : 8 samples
1 : 16 samples
2 : 32 samples
3 : 64 samples
5:0 AGC_REF[5:0] 20 R/W Target value for the AGC control loop, given in 2 dB steps.
Reset value corresponds to approximately 25% of the ADC
dynamic range in reception.
AGCTST2 (0x26) - AGC Test Register 2
Bit Field Name Reset R/W Description
15:10 - 0 W0 Reserved, write as 0
9:5 MED2HIGHGAIN[4:0] 9 R/W MED2HIGHGAIN sets the difference in the receiver
LNA/MIXER gain from medium gain mode to high gain mode,
used by the AGC for setting the correct front-end gain mode.
4:0 LOW2MEDGAIN[4:0] 10 R/W LOW2MEDGAIN sets the difference in the receiver
LNA/MIXER gain from low gain mode to medium gain mode,
used by the AGC for setting the correct front-end gain mode.