MC33596_10 Datasheet, PDF (37/70 Pages) Freescale Semiconductor, Inc – PLL Tuned UHF Receiver for Data Transfer Applications

Register Description
ILA1
0
0
1
1
Table 11. RF Input Level Attenuation
ILA0
0
1
0
1
RF Input Level
Attenuation
0 dB
8 dB
16 dB
30 dB
See Parameter
Number
2.5
2.6
2.7
2.8
Values in Table 11 assume the LNA gain is not reduced by the AGC.
AFF[1:0] (Average Filter Frequency) define the average filter cut-off frequency if the AFFC bit is set.
Table 12. Average Filter Cut-off Frequency
AFF1
0
0
1
1
AFF0
0
1
0
1
Average Filter Cut-off
Frequency
0.5 kHz
1 kHz
2 kHz
4 kHz
If AFFC is reset, the average filter frequency is directly defined by bits DR[1:0], as shown in Table 10.
If AFFC is set, AFF[1:0] allow the overall receiver sensitivity to be improved by reducing the average
filter cut-off frequency. The typical preamble duration of three Manchester zeroes or ones at the data rate
must then be increased, as shown in Table 13.
Table 13. Minimum Number of Manchester Symbols in Preamble
versus DR[1:0] and AFF[1:0]
DR[1:0]
00
01
10
11
00
3
6
12
24
01
—
3
6
12
AFF[1:0]
10
—
—
3
6
11
—
—
—
3
16.2 Command Register
Figure 27 describes the Command register, COMMAND.
MC33596 Data Sheet, Rev. 4
Freescale Semiconductor
37