RXC101 Datasheet, PDF (17/33 Pages) RF Monolithics, Inc – Multi-channel High data rate Programmable

Configuration Register [POR=893Ah]
Bit Bit Bit Bit
Bit
Bit
Bit
Bit
Bit Bit Bit Bit Bit Bit Bit Bit
15 14 13 12
11
10
9
8
7
6
5
4
321
0
1 0 0 ^{BAND1 BAND0 LBDEN WKUPEN OSCEN CAP3 CAP2 CAP1 CAP0 BB2 BB1 BB0 CLKEN}
The configuration register sets up the following:
• Internal Data Register
• Internal FIFO
• Frequency Band in use
• Crystal Load capacitance
Bit [15..13] – Command Code: These bits are the command code that is sent serially to the processor
that identifies the bits to be written to the configuration register.
Bit [12..11] – Band Select: These bits set the frequency band to be used. There are four (4) bands that
are supported. See Table 4 for Band configuration.
TABLE 4.
Frequency Band BAND1
315
0
433
0
868
1
916
1
BAND0
0
1
0
1
Bit [10] – Low Battery Detector: This bit enables the battery voltage detect circuit when set. The battery
detector can be programmed to 32 different threshold levels. See Battery Detect Threshold and
Clock Output Register section for programming.
Bit [9] – Wake-up Timer Enable: This bit enables the wake-up timer when set. See Wake-up Timer
Period Register section for programming the wake-up timer interval value.
Bit [8] – Crystal Oscillator: This bit enables the oscillator circuit when set. The oscillator provides the
reference signal for the synthesizer when setting the transmit or receive frequency of use.
Bit [7..4] – Load Capacitance Select: These bits set the load capacitance for the crystal reference. The
internal load capacitance can be varied from 8.5pF to 16pF in .5pF steps to accommodate a wide
range of crystal vendors as well as adjust the reference frequency and compensate for stray
capacitance that may be introduced due to PCB layout. See Table 5 for load capacitance
configuration.
TABLE 5.
CAP3 CAP2 CAP1 CAP0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
……
1
1
1
0
1
1
1
1
Crystal Load
Capacitance
8.5
9
9.5
10
……
15.5
16
17