RFM TRC105

TRC105
Product Overview
TRC105 is a single chip, multi-channel, low power UHF transceiver. It is
designed for low cost, high volume, two-way short range wireless applications in the 300 to 510 MHz frequency range. The TRC105 is FCC & ETSI
certifiable. All critical RF and base-band functions are integrated in the
TRC105, minimizing external component count and simplifying and speeding
design-ins. A microcontroller, RF SAW filter, 12.8 MHz crystal and a few passive components are all that is needed to create a complete, robust radio
function. The TRC105 incorporates a set of low-power states to reduce current consumption and extend battery life. The small size and low power consumption of the TRC105 make it ideal for a wide variety of short range radio
applications. The TRC105 complies with Directive 2002/95/EC (RoHS). Pb
300-510 MHz
RF Transceiver
Key Features























Modulation: FSK or OOK with frequency hopping spread spectrum capability
Frequency range: 300 to 510 MHz
High sensitivity: -112 dBm in circuit
High data rate: up to 200 kb/s
Low receiver current: 2.7 mA typical
Low sleep current: 0.1 µA typical
Up to +13 dBm in-circuit transmit power
Operating supply voltage: 2.1 to 3.6 V
Programmable preamble
Programmable packet start pattern
Integrated RF, PLL, IF and base-band circuitry
Integrated data & clock recovery
Programmable RF output power
PLL lock output
Transmit/receive FIFO size programmable up
to 64 bytes
Continuous, buffered and packet data modes
Packet address recognition
Packet handling features:
 Fixed or variable packet length
 Packet filtering
 Packet formatting
Standard SPI interface
TTL/CMOS compatible I/O pins
Programmable clock output frequency
Low Battery Detection
Low cost 12.8 MHz crystal reference
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.














Integrated RSSI
Integrated crystal oscillator
Host processor interrupt pins
Programmable data rate
External wake-up event inputs
Integrated packet CRC error detection
Integrated DC-balanced data scrambling
Integrated Manchester encoding/decoding
Interrupt signal mapping function
Support for multiple channels
Four power-saving modes
Low external component count
TQFN-32 SMT package
Standard 13 inch reel, 3K pieces
Applications












Active RFID tags
Automated meter reading
Home & industrial automation
Security systems
Two-way remote keyless entry
Automobile immobilizers
Sports performance monitoring
Wireless toys
Medical equipment
Low power two-way telemetry systems
Wireless mesh sensor networks
Wireless modules
Technical support +1.800.704.6079
Page 1 of 67
TRC105 - 10/16/12
Table of Contents
1.0 Pin Configuration .....................................................................................................................................4
1.1 Pin Description ..................................................................................................................................4
2.0 Functional Description .............................................................................................................................5
2.1 RF Port ..............................................................................................................................................7
2.2 Transmitter ........................................................................................................................................7
2.3 Receiver ............................................................................................................................................8
2.4 Crystal Oscillator ...............................................................................................................................9
2.5 Frequency Synthesizer ...................................................................................................................10
2.6 PLL Loop Filter ................................................................................................................................11
3.0 Operating Modes ...................................................................................................................................11
3.1 Receiving in Continuous Data Mode...............................................................................................12
3.2 Continuous Mode Data and Clock Recovery ..................................................................................14
3.3 Continuous Mode Start Pattern Detect ...........................................................................................14
3.4 RSSI ................................................................................................................................................15
3.5 Receiving in Buffered Data Mode ...................................................................................................15
3.6 Transmitting in Continuous or Buffered Data Modes ......................................................................17
3.7 IRQ0 and IRQ1 Mapping.................................................................................................................18
3.8 Buffered Clock Output .....................................................................................................................19
3.9 Packet Data Mode...........................................................................................................................19
3.9.1 Fixed Length Packet Mode ....................................................................................................19
3.9.2 Variable Length Packet Mode ...............................................................................................20
3.9.3 Extended Variable Length Packet Mode ...............................................................................20
3.9.4 Packet Payload Processing in Transmit and Receive ...........................................................22
3.9.5 Packet Filtering ......................................................................................................................23
3.9.6 Cyclic Redundancy Check.....................................................................................................23
3.9.7 Manchester Encoding ............................................................................................................24
3.9.8 DC-Balanced Scrambling ......................................................................................................25
3.10 SPI Configuration Interface ...........................................................................................................25
3.11 SPI Data FIFO Interface ...............................................................................................................27
4.0 Configuration Register Memory Map .....................................................................................................29
4.1 Main Configuration Registers (MCFG)............................................................................................30
4.2 Interrupt Configuration Registers (IRQCFG)...................................................................................33
4.3 Receiver Configuration Registers (RXCFG) ...................................................................................35
4.4 Start Pattern Configuration Registers (SYNCFG) ...........................................................................38
4.5 Transmitter Configuration Registers (TXCFG)................................................................................38
4.6 Oscillator Configuration Register (OSCFG) ....................................................................................39
4.7 Packet Handler Configuration Registers (PKTCFG) .......................................................................39
4.8 Page Configuration Register (PGCFG)...........................................................................................40
4.9 Low Battery Configuration Registers (LBCFG) ...............................................................................41
5.0 Electrical Characteristics .......................................................................................................................42
5.1 DC Electrical Characteristics ..........................................................................................................42
5.2 AC Electrical Characteristics ...........................................................................................................43
6.0 TRC105 Design-In Steps.......................................................................................................................45
6.1 Determining Frequency Specific Hardware Component Values ....................................................45
6.1.1 SAW Filters and Related Component Values .......................................................................45
6.1.2 Voltage Controlled Oscillator Component Values .................................................................46
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 2 of 67
TRC105 - 10/16/12
6.2 Determining Configuration Values for FSK Modulation ..................................................................46
6.2.1 Bit Rate Related FSK Configuration Values ..........................................................................46
6.2.2 Determining Transmitter Power Configuration Values ..........................................................48
6.3 Determining Configuration Values for OOK Modulation .................................................................49
6.3.1 Bit Rate Related OOK Configuration Values ........................................................................49
6.3.2 OOK Demodulator Related Configuration Values .................................................................51
6.3.3 OOK Transmitter Related Configuration Values ...................................................................52
6.4 Frequency Synthesizer Channel Programming for FSK Modulation ..............................................53
6.5 Frequency Synthesizer Channel Programming for OOK Modulation .............................................54
6.6 TRC105 Data Mode Selection and Configuration ...........................................................................55
6.6.1 Continuous Data Mode ..........................................................................................................55
6.6.2 Buffered Data Mode ..............................................................................................................57
6.6.3 Packet Data Mode .................................................................................................................59
6.7 Battery Power Management Configuration Values .........................................................................63
7.0 Package Dimensions and Typical PCB Footprint - QFN-32 .................................................................65
8.0 Tape and Reel Dimensions ...................................................................................................................66
9.0 Solder Reflow Profile .............................................................................................................................67
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 3 of 67
TRC105 - 10/16/12
V D D
2 9
G N D
3
3 0
V D D _ D IG
V D D _ V C O
3 1
V D D _ A N A
2
V D D _ P A
G N D
3 2
R F -
1
G N D
G N D
R F +
1.0 Pin Configuration
2 8
2 7
2 6
2 5
4
T A N K +
5
P L L -
G N D P A D
O N B O T T O M
O F P A C K A G E
T A N K -
2 4
n L O W _ B A T
2 3
P L L _ L O C K
2 2
IR Q 1
2 1
IR Q 0
S C K
1 7
S D I
G N D
9
1 0
1 1
1 2
1 3
1 4
1 5
1 6
S D O
1 8
8
n S S _ D A T A
7
G N D
n S S _ C O N F IG
P L L +
N C
C L K O U T
G N D
1 9
X T A L +
D A T A
6
X T A L -
2 0
1.1 Pin Description
PIN
TYPE
NAME
DESCRIPTION
1
2
-
GND
CONNECT TO GND
-
GND
CONNECT TO GND
3
O
VDD_VCO
REGULATED SUPPLY FOR VCO
4
I/O
TANK-
VCO TANK
5
I/O
TANK+
VCO TANK
6
I/O
PLL-
PLL LOOP FILTER OUTPUT
7
I/O
PLL+
PLL LOOP FILTER INPUT
8
-
GND
CONNECT TO GND
9
-
GND
CONNECT TO GND
10
I/O
XTAL+
CRYSTAL CONNECTION (OSCILLATOR OUTPUT)
11
I/O
XTAL-
CRYSTAL CONNECTION (OSCILLATOR INPUT)
12
-
GND
CONNECT TO GND
13
-
NC
NO CONNECTION - FLOAT PIN
14
I
nSS_CONFIG
SLAVE SELECT FOR SPI CONFIGURATION DATA
15
I
nSS_DATA
SLAVE SELECT FOR SPI TX/RX DATA
16
O
SDO
SERIAL DATA OUT
17
I
SDI
SERIAL DATA IN
18
I
SCK
SERIAL SPI CLOCK IN
19
O
CLKOUT
BUFFERED CLOCK OUTPUT
20
I/O
DATA
TRANSMIT/RECEIVE DATA
21
O
IRQ0
INTERRUPT OUTPUT
22
O
IRQ1/DCLK
INTERRUPT OUTPUT/RECOVERED DATA CLOCK (CONT MODE)
23
O
PLL_LOCK
PLL LOCKED INDICATOR
24
O
nLOW_BATT
LOW BATTERY DETECT (LEAVE UNCONNECTED IF NOT USED)
25
-
GND
CONNECT TO GND
26
I
VDD
MAIN 3.3 V SUPPLY VOLTAGE
27
O
VDD_ANA
REGULATED SUPPLY FOR ANALOG CIRCUITRY
28
O
VDD_DIG
REGULATED SUPPLY FOR DIGITAL CIRCUITRY
29
O
VDD_PA
REGULATED SUPPLY FOR RF POWER AMP
30
-
GND
CONNECT TO GND
31
I/O
RF-
RF I/O
32
I/O
RF+
RF I/O
PAD
-
GROUND
GROUND PAD ON PKG BOTTOM
Table 1
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 4 of 67
TRC105 - 10/16/12
2.0 Functional Description
The TRC105 is a single-chip transceiver that can operate in the 300-510 MHz frequency range. The TRC105
supports two modulation schemes - FSK and OOK. The TRC105’s highly integrated architecture requires a minimum of external components, while maintaining design flexibility. All major RF communication parameters are
programmable and most can be dynamically set. The TRC105 is optimized for very low power consumption (2.7
mA typical in receiver mode). It complies with European ETSI, FCC Part 15 and Canadian RSS-210 regulatory
standards. Advanced digital features including the TX/RX FIFO and the packet handling data mode significantly
reduce the load on the host microcontroller.
T R C 1 0 5 B lo c k D ia g r a m
T X L O 1 -I
+
T X L O 2 -I
O O K
M o d u la tio n
In p u t
-
T X L O 2 -Q
A n tia lia s in g
F ilte r
D A C
+
R F +
P o w e r
A m p
R F -
T r a n s m it
W a v e fo rm
G e n e ra to r
D r iv e r
A n tia lia s in g
F ilte r
+
D A C
T X L O 2 -I
+
T X L O 2 -Q
T X L O 1 -Q
O O K
D e te c to r
R S S I
R X L O 2 -I
R -C
L o w -p a s s
F ilte r
L N A
R e c e iv e r
B a n d -p a s s
F ilte r
B u tte rw o rth
o r
P o ly p h a s e
F ilte r
IF A m p lifie r
S C K
S D I
D a ta &
C lo c k
R e c o v e ry
L im ite r
S D O
n S S _ D A T A
C o n tro l
R -C
L o w -p a s s
F ilte r
R X L O 1
D A T A
IR Q 1 /D C L K
F S K
D e te c to r
V G A
n S S _ C O N F IG
IR Q 0
P L L _ L O C K
B u tte rw o rth
o r
P o ly p h a s e
F ilte r
IF A m p lifie r
L im ite r
R X L O 2 -Q
O s c illa to r
D iv id e r &
B u ffe r
C L K O U T
V C O
F re q u e n c y
D iv id e r
T X L O 2 -I
D iv id e
b y 8
T X L O 2 -Q
T X L O 1 -I
C ry s ta l
O s c illa to r
R e fe re n c e
F re q u e n c y
D iv id e r
C h a rg e
P u m p
P h a s e
D e te c to r
P L L
L o o p
F ilte r
I & Q
P h a s e
V C O
T X L O 1 -Q
F IF O
R X L O 1
D iv id e
b y 8
R X L O 2 -I
R X L O 2 -Q
V C O -
V C O +
P L L +
P L L -
X T A L +
X T A L -
Figure 1
The receiver is based on a superheterodyne architecture. It is composed of the following major blocks:

An LNA that provides low noise RF gain followed by an RF band-pass filter.

A first mixer which down-converts the RF signal to an intermediate frequency equal to 1/9th of the carrier
frequency.

A variable gain first IF preamplifier followed by two second mixers which down convert the first IF signal to
I and Q signals at a low frequency (zero-IF for FSK, low-IF for OOK).
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 5 of 67
TRC105 - 10/16/12

A two-stage IF filter followed by an amplifier chain for both the I and Q channels. Limiters at the end of
each chain drive the I and Q inputs to the FSK demodulator function. An RSSI signal is also derived from
the I and Q IF amplifiers to drive the OOK detector. The second filter stage in each channel can be configured as either a third-order Butterworth low-pass filter for FSK operation or an image reject polyphase
band-pass filter for OOK operation.

An FSK arctangent type demodulator driven from the I and Q limiter outputs, and an OOK demodulator
driven by the RSSI signal. Either detector can drive a data and clock recovery function that provides
matched filter enhancement of the demodulated data.
The transmitter chain is based on the same double-conversion architecture and uses the same intermediate frequencies as the receiver chain. The main blocks include:

A digital waveform generator that provides the I and Q base-band signals. This block includes digital-toanalog converters and anti-aliasing low-pass filters.

A compound image-rejection mixer to up convert the base-band signal to the first IF at 1/9th of the carrier
frequency, and a second image-rejection mixer to up-convert the IF signal to the RF frequency

Transmitter driver and power amplifier stages to drive the antenna port
The frequency synthesizer is based on an integer-N PLL having a typical frequency step size of 12.5 kHz. Two
programmable frequency dividers in the feedback loop of the PLL and one programmable divider on the reference
oscillator allow the LO frequency to be adjusted. The reference frequency is generated by a crystal oscillator running at 12.8 MHz.
The TRC105 is controlled by a digital block that includes registers to store the configuration settings of the radio.
These registers are accessed by a host microcontroller through an SPI style serial interface. The microcontroller’s
serial connections to the TRC105’s SDI, SDO and SCK pins are shown in Figure 2 (component values shown are
for 418.00-434.79 MHz operation; see Tables 57 and 58 for other frequency bands). On-chip regulators provide
stable supply voltages to sensitive blocks and allow the TRC105 to be used with supply voltages from 2.1 to
3.6 V. Most blocks are supplied with a voltage below 1.6 V.
C17
1.2 pF
C16
DNP
Figure 2
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 6 of 67
TRC105 - 10/16/12
2.1 RF Port
The receiver and the transmitter share the same RF pins. Figure 3 shows the implementation of the common
front-end. In transmit mode, the PA and the PA regulator are on; the voltage on VDD_PA pin is the nominal voltage of the regulator, about 1.8 V. The external inductances L1 and L4 are used for the PA. In receive mode, both
PA and PA regulator are off, and VDD_PA is tied to ground. The external inductances L1 and L4 are used for biasing and matching the LNA, which is implemented as a common gate amplifier.
In te r n a l R F P o r t D e ta il
V D D _ P A
V R E G
R X O N
L 1
A n te n n a
L 4
P o w e r
A m p
S A W
F ilte r
+
D r iv e r
+
L N A
R e c e iv e r
Figure 3
2.2 Transmitter
The TRC105 is set to transmit mode when MCFG00_Chip_Mode[7..5] bits are set to 100. In Continuous data
mode the transmitted data is sent directly to the modulator. The host microcontroller is provided with a bit rate
clock by the TRC105 to clock the data; using this clock to send the data synchronously is mandatory in FSK configuration and optional in OOK configuration. In Buffered and Packet data modes the data is first written into the
64-byte FIFO via the SPI interface; data from the FIFO is then used by the modulator.
At the front end of the transmitter, I and Q signals are generated by the base-band circuit which contains a digital
waveform generator, two D/A converters and two anti-aliasing low-pass filters. The I and Q signals are two quadrature sinusoids whose frequency is the selected frequency deviation. In FSK mode, the phase shift between I
and Q is switched between +90° and -90° according to the input data. The modulation is then performed at this
stage, since the information contained in the phase shift will be converted into a frequency shift when the I and Q
signals are combined in the first mixers. In OOK mode, the phase shift is kept constant whatever the data. The
combination of the I and Q signals in the first mixers creates a fixed frequency signal at a low intermediate frequency which is equal to the selected frequency deviation. After D/A conversion, both I and Q signals are filtered
by anti-aliasing filters whose bandwidth is programmed with the register TXCFG1A_TXInterpfilt[7..4]. Behind the
filters, a set of four mixers combines the I and Q signals and converts them into two I and Q signals at the second
intermediate frequency which is equal to 1/8 of the LO frequency, which in turn is equal to 8/9 of the RF frequency. These two new I and Q signals are then combined and up-converted to the desired RF frequency by two
quadrature mixers fed by the LO signals. The signal is then amplified by a driver and power amplifier stage.
MCFG05_PA_Ramp[7..6]
TPA (µs)
Rise/fall (µs)
00
3
2.5/2
01
8.5
5/3
10
15
10/6
11
23
20/10
Table 2
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 7 of 67
TRC105 - 10/16/12
OOK modulation is performed by switching on and off the power amplifier and its regulator. The rise and fall times
of the OOK signal can be configured in register MCFG05_PA_Ramp[7..6], which controls the charge and discharge time of the regulator. Figure 4 shows the time constants set by MCFG05_PA_Ramp[7..6]. Table 2 gives
typical values of the rise and fall times as defined in Figure 4 when the capacitance connected to the output of the
regulator is 0.047 µF.
O O K M o d u la tio n
W a v e fo rm s
D A T A
P o w e r A m p
R e g u la to r
9 5 %
R is e /F a ll
T im e s
R F E n v e lo p e
6 0 d B
R is e /F a ll
T im e s
Figure 4
2.3 Receiver
The TRC105 is set to receive mode when MCFG00_Chip_Mode[7..5] is set to 011. The receiver is based on a
double-conversion architecture. The front-end is composed of an LNA and a mixer whose gains are constant. The
mixer down-converts the RF signal to an intermediate frequency which is equal to 1/8 of the LO frequency, which
in turn is equal to 8/9 of the RF frequency. Behind this first mixer there is a variable gain IF amplifier that can be
programmed from maximum gain to 13.5 dB less in 4.5 dB steps with the MCFG01_IF_Gain[1..0] register.
After the variable gain IF amplifier, the signal is down-converted into two I and Q base-band signals by two quadrature mixers which are fed by reference signals at 1/8 the LO frequency. These I and Q signals are then filtered
and amplified before demodulation. The first filter is a second-order passive R-C filter whose bandwidth can be
programmed to 16 values with the register RXCFG10_LP_filt[7..4]. The second filter can be configured as either
a third-order Butterworth active filter which acts as a low-pass filter for the zero-IF FSK configuration, or as a polyphase band-pass filter for the low-IF OOK configuration. To select Butterworth low-pass filter operation, bit
RXCFG12_PolyFilt_En[7] is set to 0. The bandwidth of the Butterworth filter can be programmed to 16 values
with the register RXCFG10_BW_Filt[3..0]. The low-IF configuration must be used for OOK modulation. This configuration is enabled when the bit RXCFG12_PolyFilt_En[7] is set to 1. The center frequency of the polyphase
filter can be programmed to 16 values with the register RXCFG11_PolyFilt[7..4]. The bandwidth of the filter can
be programmed with the register RXCFG10_BW_Filt[3..0]. In OOK mode, the value of the low-IF is equal to the
deviation frequency defined in register MCFG02_Freq_dev. In addition to channel filtering, the function of the
polyphase filter is to reject the image. Figure 5 below shows the two configurations of the second IF filter. In the
Butterworth configuration, FCBW is the 3 dB cutoff frequency. In the polyphase band-pass configuration FOPP is the
center frequency given by RXCFG11_PolyFilt[7..4], and FCPP is the upper 3 dB bandwidth of the filter whose offset, referenced to FOPP, is given by RXCFG10_BW_Filt[3..0].
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 8 of 67
TRC105 - 10/16/12
T R C 1 0 5 S e c o n d IF F ilte r D e ta ils
F
C B W
B u tte r w o th L o w -p a s s F ilte r fo r F S K
2 *F
O P P
- F
C P P
F
F
O P P
C P P
P o ly p h a s e B a n d -p a s s F ilte r fo r O O K
Figure 5
After filtering, the I and Q signals are each amplified by a chain of 11 amplifiers having 6 dB of gain each. The
outputs of these amplifiers and their intermediate 3 dB nodes are used to evaluate the received signal strength
(RSSI). Limiters are located behind the 11 amplifiers of the I and Q chains and the signals at the output of these
limiters are used by the FSK demodulator. The RSSI output is used by the OOK demodulator. The global bandwidth of the whole base-band chain is given by the bandwidths of the passive filter, the Butterworth filter, the amplifier chain and the limiter. The maximum achievable global bandwidth when the bandwidths of the first three
blocks are programmed at their upper limit is about 350 kHz.
2.4 Crystal Oscillator
Crystal specifications for the TRC105 reference oscillator are given in Table 3. RFM recommends the XTL1020P
crystal which is specifically designed for use with the TRC105. Note that crystal frequency error will directly translate to carrier frequency, bit rate and frequency deviation error.
Specification
Min
Typical
Max
Units
-
12.80000
(fundamental)
-
MHz
13.5
15
16.5
pF
Motional resistance
-
-
50
Ω
Motional capacitance
5
-
20
fF
Shunt capacitance
1
-
Calibration tolerance at 25 °C
-
Stability over temperature range
(-40 °C to 85 °C)
1
Aging in first 5 years
-
Nominal frequency
Load capacitance for Fs
7
pF
±10
ppm (1)
-
±15
ppm
-
±2
ppm/yr
Table 3
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 9 of 67
TRC105 - 10/16/12
2.5 Frequency Synthesizer
The TRC105 VCO operating frequency range is covered in six bands. Operation in each band requires a specific
VCO inductor value and configuration parameter setting, as shown in Table 4 below:
MCFG00_Band[4..2]
Frequency Band MHz
000
300-330
001
330-365
010
365-400
011
400-440
100
440-470
101
470-510
110 to 111
not used
Table 4
Each of these bands is divided into four subbands to provide a low phase noise VCO frequency trimming mechanism. Subbands are selected as shown in Table 5 below:
MCFG00_Subband[1..0]
Subband
00
1 quarter
01
2 quarter
400-440 MHz example
st
400-410
nd
410-420
rd
420-430
th
430-440
10
3 quarter
11
4 quarter
Table 5
Using the VCO as discussed above, the frequency synthesizer generates the local oscillator (LO) signal for the
receiver and transmitter sections. The core of the synthesizer is implemented with an integer-N PLL architecture.
The frequency is set by three divider parameters R, P and S. R is the frequency divider ratio in the reference frequency path. P and S set the frequency divider ratio in the feedback loop of the PLL. The frequency synthesizer
includes a crystal oscillator which provides the frequency reference for the PLL. The equations giving the relationships between the reference crystal frequency, the local oscillator frequency and RF carrier frequency are given
below:
FLO = FXTAL*(75*(P + 1) + S)/(R + 1), with P and S in the range 0 to 255, S less than (P + 1), R in the
range 64 to 169, and FLO and FXTAL in MHz.
FRF = 1.125*FLO, where FRF and FLO are in MHz
FLO is the first local oscillator (VCO) frequency, FXTAL is the reference crystal frequency and FRF is the RF channel
frequency. FLO is the frequency used for the first down-conversion of the receiver and the second up-conversion of
the transmitter. The intermediate frequency used for the second down-conversion of the receiver and the first upconversion of the transmitter is equal to 1/8 of FLO. As an example, with a crystal frequency of 12.8 MHz and an
RF frequency of 434 MHz, FLO is 385.8 MHz and the first IF of the receiver is 48.2 MHz.
There are two sets of divider ratio registers: SynthR1[7..0], SynthP1[7..0], SynthS1[7..0], and SynthR2[7..0],
SynthP2[7..0], SynthS2[7..0]. The MCFG05_RF_Freq[0] bit is used to select which set of registers to use as the
current frequency setting. For frequency hopping applications, this reduces the programming and synthesizer settling time when changing frequencies. While the data is being transmitted, the next frequency is programmed and
ready. When the current transaction is complete, the MCFG05_RF_Freq[0] bit is complemented and the frequency shifts to the next freq according to the contents of the divider ratio registers. This process is repeated for each
frequency hop.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 10 of 67
TRC105 - 10/16/12
2.6 PLL Loop Filter
The loop filter for the frequency synthesizer is shown in Figure 6.
PLL Loop Filter
PLL Loop Filter Components
Name
Value
Tolerance
C8
1000 pF
±10%
C9
6800 pF
±10%
R1
6.8 kΩ
±5%
Table 6
Figure 6
Recommended component values for the frequency synthesizer loop filter are provided in Table 6. The loop filter
settings are not dependent on the frequency band, so they can be used on all designs. PLL lock status can be
provided on Pin 23 by setting the IRQCFG0E_PLL_LOCK_EN[0] bit to a 1. Pin 23 goes high when the PLL is
locked. The lock status of the PLL can also be checked by reading the IRQCFG0E_PLL_ LOCK_ST[1] bit. This
bit latches high each time the PLL locks and must be reset by writing a 1 to it.
3.0 Operating Modes
The TRC105 has 5 possible chip-level modes. The chip-level mode is set by MCFG00_Chip_Mode[7..5], which
is a 3-bit pattern in the configuration register. Table 7 summarizes the chip-level modes:
MCFG00_Chip_Mode[7..5]
Chip-level Mode
000
Sleep
Enabled Functions
001
Standby
010
Synthesizer
011
Receive
Crystal, frequency synthesizer and receiver
100
Transmit
Crystal, frequency synthesizer and transmitter
None
Crystal oscillator
Crystal and frequency synthesizer
Table 7
Table 8 gives the state of the digital pins for the different chip-level modes and settings:
PIN Function
Sleep
Mode
Standby
Mode
Synthesizer
Mode
Receive
Mode
Transmit
Mode
nSS_CONFIG*
I
I
I
I
I
nSS_DATA*
I
I
I
I
I
IRQ0
TRI
O
O
O
O
IRQ1
TRI
O
O
O
O
DATA
TRI
TRI
TRI
O
I
CLKOUT
SDO**
TRI
O
O
O
O
TRI/O
TRI/O
TRI/O
TRI/O
TRI/O
SDI
I
I
I
I
I
SCK
I
I
I
I
I
I = Input, O = Output, TRI = High Impedance
*nSS_CONFIG has priority OVER nSS_DATA
**SDO is an output if nSS CONFIG = 0 and/or nSS DATA = 0
Table 8
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 11 of 67
TRC105 - 10/16/12
The TRC105 transmitter and receiver sections support three data handling modes of operation:

Continuous mode: each bit transmitted or received is accessed directly at the DATA input/output pin.

Buffered mode: a 64-byte FIFO is used to store each data byte transmitted or received. This data is written to and read from the FIFO through the SPI bus.

Packet handling mode: in addition to using the FIFO, this data mode builds the complete packet in
transmit mode and extracts the useful data from the packet in receive mode. The packet includes a preamble, a start pattern (network address), an optional node address and length byte and the data. Packet
data mode can also be configured to perform additional operations like CRC error detection and DCbalanced Manchester encoding or data scrambling.
The buffered and packet handling modes allow the host microcontroller overhead to be significantly reduced.
The DATA pin is bidirectional and is used in both transmit and receive modes. In receive mode, DATA represents
the demodulated received data. In transmit mode, input data is applied to this pin.
The working length of the FIFO can set to 16, 32, 48 or 64 bytes through the MCFG0C_FIFO_depth[7..6] register. In the discussions below describing the FIFO behavior, the explanations are given with an assumption of 64
bytes, but the principle is the same for the four possible FIFO sizes.
The status of the FIFO can be monitored via interrupts which are described in Section 3.7. In addition to the
straightforward nFIFOEMPY and FIFOFULL interrupts, additional configurable interrupts Fifo_Int_Tx and
Fifo_Int_Rx are also available.
A low-to-high transition occurs on Fifo_Int_Rx when the number of bytes in the FIFO is greater than or equal to
the threshold set by MCFG0C_FIFO_thresh[5..0] (number of bytes ≥ FIFO_thresh).
A low-to-high transition occurs on Fifo_Int_Tx when the number of bytes in the FIFO is less than or equal to the
threshold set by MCFG0C_FIFO_thresh[5..0] (number of bytes ≤ FIFO_thresh).
3.1 Receiving in Continuous Data Mode
The receiver operates in Continuous data mode when the MCFG01_Mode[7..6] bits are set to 00. In this mode,
the receiver has two output signals indicating recovered clock, DCLK and recovered NRZ bit DATA. DCLK is connected to output pin IRQ1 and DATA is connected to pin DATA configured in output mode. The data and clock
recovery controls the recovered clock signal, DCLK. Data and clock recovery is enabled by RXCFG12_DCLK_
Dis[6] to 0 (default value). The clock recovered from the incoming data stream appears at DCLK. When data and
clock recovery is disabled, the DCLK output is held low and the raw demodulator output appears at DATA. The
function of data and clock recovery is to remove glitches from the data stream and to provide a synchronous clock
at DCLK. The output DATA is valid at the rising edge of DCLK as shown in Figure 8.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 12 of 67
TRC105 - 10/16/12
T R C 1 0 5 C o n tin u o u s M o d e D e m o d u la tio n
R E C O G
R S S I_ IR Q
S ta rt
P a tte rn
D e te c t
O O K
D e te c to r
R S S I
IR Q 0
R X _ IR Q 0
IF A m p lifie r
D a ta &
C lo c k
R e c o v e ry
L im ite r
D C L K
(IR Q 1 )
D A T A
F S K /O O K
F S K
D e te c to r
D C L K _ D IS
IF A m p lifie r
L im ite r
Figure 7
As shown in Figure 7, the demodulator section includes the FSK demodulator, the OOK demodulator, data and
clock recovery and the start pattern detection blocks.
If FSK is selected, the demodulation is performed by analyzing the phase between the I and Q limited signals at
the output of the base-band channels.
If OOK is selected, the demodulation is performed by comparing the RSSI output value stored in RXCFG14_
RSSI[7..0] register to the threshold which can be either a fixed value or a time-variant value depending on the
past history of the RSSI output. Table 9 gives the three main possible procedures, which can be selected via the
register MCFG01_RX_OOK[3..2]:
Mode
MCFG01_RX_OOK[3..2]
Fixed Threshold
00
Peak
01
Average
10
Description
RSSI output is compared with a fixed threshold stored in
RXCFG13_OOK_thresh
RSSI output is compared with a threshold which is at a fixed offset
below the maximum RSSI.
RSSI output is compared with the average of the last RSSI values.
Table 9
If the end-user application requires direct access to the output of the demodulator, then the RXCFG12_DCLK_
Dis[6] bit is set to 1 disabling the clock recovery. In this case the demodulator output is directly connected to the
DATA pin and the IRQ1 pin (DCLK) is set to low.
For proper operation of the TRC105 demodulator in FSK mode, the modulation index β of the input signal should
meet the following condition:
2*FDEV
β=
≥2
BR
where FDEV is the frequency deviation in hertz (Hz) and BR is the data rate in bits per second (b/s).
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 13 of 67
TRC105 - 10/16/12
3.2 Continuous Mode Data and Clock Recovery
The raw output signal from the demodulator may contain jitter and glitches. Data and clock recovery converts the
data output of the demodulator into a glitch-free bit-stream DATA and generates a synchronized clock DCLK to be
used for sampling the DATA output as shown in Figure 8. DCLK is available on pin IRQ1 when the TRC105 operates in continuous mode.
D a ta & C lo c k R e c o v e r y T im in g
D A T A
D C L K
D A T A v a lid o n r is in g e d g e o f D C L K
Figure 8
To ensure correct operation of the data and clock recovery circuit, the following conditions have to be satisfied:

A 1-0-1-0… preamble of at least 24 bits is required for synchronization

The transmitted bit stream must have at least one transition from 0 to 1 or from 1 to 0 every 8 bits during
transmission

The bit rate accuracy must be better than 2 %.
Data and clock recovery is enabled by default. It is controlled by RXCFG12_DCLK_Dis[6]. If data and clock recovery is disabled, the output of the demodulator is directed to DATA and the DCLK output (IRQ1 Pin in continuous mode) is set to 0.
The received bit rate is defined by the values of the MCFG03 and MCFG04 configuration registers, and is calculated as follows:
BR = FXTAL/(2*(C + 1)*(D + 1)), with C in the range of 0 to 255, and D = 31 (suitable for most applications)
with BR the bit rate in kb/s, FXTAL the crystal frequency in kHz, C the value in MCFG03, and D the value in
MCFG04. For example, using a 12.8 MHz crystal (12,800 kHz), the bit rate is 25 kb/s when C = 7 and D = 31.
3.3 Continuous Mode Start Pattern Detection
Start pattern detection is activated by setting the RXCFG12_Recog[5] bit to 1. The demodulated signal is compared with a pattern stored in the SYNCFG registers. The Start Pattern Detect signal (PATTERN) is driven by the
output of this comparator and is synchronized by DCLK. It is set to 1 when a pattern match is detected, otherwise
set to 0. The pattern detect output is updated at the rising edge of DCLK. The number of bytes used for comparison is defined in the RXCFG12_Pat_sz[4..3] register and the number of tolerated bit errors for pattern detection
is defined in the RXCFG12_Ptol[2..1] register. Figure 9 illustrates the pattern detection process.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 14 of 67
TRC105 - 10/16/12
S ta r t P a tte r n D e te c tio n T im in g
D A T A
B it 0
B it 1
B it N -1
B it N
B it N + 1
D C L K
P A T T E R N
D E T E C T
Figure 9
Note that start pattern detection is enabled only if data and clock recovery is enabled.
3.4 RSSI
The received signal strength is measured in the amplifier chains behind the second mixers. Each amplifier chain
is composed of 11 amplifiers each having a gain of 6 dB and an intermediate output at 3 dB. By monitoring the
two outputs of each stage, an estimation of the signal strength with a resolution of 3 dB and a dynamic range of
63 dB is obtained. This estimation is performed 16 times over a period of the I and Q signals and the 16 samples
are averaged to obtain a final RSSI value with a 0.5 dB step. The period of the I and Q signal is the inverse of the
deviation frequency, which is the low-IF frequency in OOK mode. The RSSI effective dynamic range can be increased to 70 dB by adjusting MCFG01_IF_Gain[1..0] for less gain on high signal levels.
The RSSI block can also be used in interrupt mode by setting the bit IRQCFG0E_RSSI_Int[3] to 1. When
RXCFG14_RSSI is equal or greater than a predefined value stored in IRQCFG0F_RSSI_thld, bit IRQCFG0E_
SIG_DETECT[2] goes high and an interrupt signal RSSI_IRQ is generated on pin IRQ0 if IRQCFG0D_RX_
IRQ0[7..6] is set to 01 (see Table 10). The interrupt is cleared by writing a 1 to bit IRQCFG0E_ SIG_DETECT[2].
If the bit RSSI_IRQ remains high, the process starts again. Figure 10 shows the timing diagram of RSSI in interrupt mode.
T R C 1 0 5 R S S I In te r r u p t O p e r a tio n
R S S I T h r e s h o ld S e t to 3 0
IR Q C F G 0 E B it 3
(R S S I_ In t)
R X C F G 1 4
(R S S I V a lu e )
X
X
2 2
IR Q C F G 0 E B it 2
(S IG _ D E T E C T )
2 8
2 6
3 1
2 9
2 5
In te r r u p t
D e te c te d
2 5
In te r r u p t
R e s e t
3 3
In te r r u p t
D e te c te d
3 1
2 1
2 4
2 2
X
In te r r u p t
R e s e t
Figure 10
3.5 Receiving in Buffered Data Mode
The receiver works in Buffered data mode when the MCFG01_Mode[7..6] bits are set to 01. In this mode, the
output of the data and clock recovery, i.e., the demodulated and resynchronized signal and the clock signal DCLK
are not sent directly to the output pins DATA and IRQ1 (DCLK). These signals are used to store the demodulated
data in blocks of 8 bits in a 64-byte FIFO. Figure 11 shows the receiver chain in this mode. The FSK and OOK
demodulators, data and clock recovery circuit and start pattern detect block work as described for Continuous
data mode, but they are used with two additional blocks, the FIFO and SPI.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 15 of 67
TRC105 - 10/16/12
T R C 1 0 5 B u ffe r d & P a c k e t M o d e D e m o d u la tio n
R S S I_ IR Q
R S S I
IF A m p lifie r
O O K
D e te c to r
R E C O G
R X _ IR Q 0
S ta rt
P a tte rn
D e te c t
D a ta &
C lo c k
R e c o v e ry
L im ite r
P A T T E R N
W r ite _ B y te
n F IF O E M P T Y
F S K /O O K
F S K
D e te c to r
IF A m p lifie r
IR Q 0
R X _ IR Q 1
F IF O
L im ite r
F IF O F U L L
IR Q 1
F IF O _ In t
D A T A
S P I_ ld
F IF O _ r d
S P I
R S S I_ IR Q
S D I
S D O
S C K
n S S _ D A T A
Figure 11
When the TRC105 is in receive mode and MCFG01_Mode [7..6 ] bits are set to 01, all of the blocks described
above are enabled. In a normal communication frame the data stream is comprised of a 24-bit preamble, a start
pattern and data. Upon receipt of a matching start pattern the receiver recognizes the start of data, strips off the
preamble and start pattern, and stores the data in the FIFO for retrieval by the host microcontroller. This automated data extraction reduces the loading on the host microcontroller.
The IRQCFG0E_Start_Fill[7] bit determines how the FIFO is filled. If IRQCFG0E_Start_Fill[7] is set to 0, data
only fills the FIFO when a start pattern is detected. Received data bits are shifted into the pattern recognition
block which continuously compares the received data with the contents of the SYNCFG registers. If a match occurs, the start pattern detect block output is set for one bit period and the IRQCFG0E_Start_Det[6] bit is also set.
This internal signal can be mapped to the IRQ0 output using interrupt signal mapping. Once a pattern match has
occurred, the start pattern detect block will remain inactive until the IRQCFG0E_Start_Det[6] bit is reset.
If IRQCFG0E_Start_Fill[7] is set to 1, FIFO filling is initiated by asserting IRQCFG0E_Start_Det[6]. Once 64
bytes have been written to the FIFO the IRQCFG0D_FIFOFULL[1] signal is set. Data should then be read out. If
no action is taken, the FIFO will overflow and subsequent data will be lost. If this occurs the IRQCFG0E_FIFO_
OVR[4] bit is set to 1. The IRQCFG0D_FIFOFULL[1] signal can be mapped to pin IRQ1 as an interrupt for a microcontroller if IRQCFG0D_RX_IRQ1[5..4] is set to 01. To recover from an overflow, a 1 must be written to
IRQCFG0D_ FIFO_OVR[4]. This clears the contents of the FIFO, resets all FIFO status flags and re-initiates pattern detection. Pattern detection can also be re-initiated during a FIFO filling sequence by writing a 1 to
IRQCFG0E_Start_Det[6].
The details of the FIFO filling process are shown in Figure 12. As the first byte is written into the FIFO, signal
IRQCFG0D_nFIFOEMPY[0] is set indicating at least one byte is present. The host microcontroller can then read
the contents of the FIFO through the SPI interface. When all data is read from the FIFO, IRQCFG0D_
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 16 of 67
TRC105 - 10/16/12
nFIFOEMPY[0] is reset. When the last bit of the 64th byte has been written into the FIFO, signal IRQCFG0D_
FIFOFULL[1] is set. Data must be read before the next byte is received or it will be overwritten.
The IRQCFG0D_nFIFOEMPY[0] signal can be used as an interrupt signal for the host microcontroller by mapping to pin IRQ0 if IRQCFG0D_RX_IRQ0[7..6] is set to 10. Alternatively, the WRITE_byte signal may also be
used as an interrupt if IRQCFG0D_RX_IRQ0[7..6] is set to 01.
Demodulation in buffered mode occurs in the same way as in continuous mode. Received data is directly read
from the FIFO and the DATA and DCLK pins are not used. Data and clock recovery in buffered mode is automatically enabled. DCLK is not externally available.
The pattern recognition block is automatically enabled in Buffered data mode. The Start Pattern Detect
(PATTERN) signal can be mapped to pin IRQ0. In Buffered data mode RSSI operates the same way as in Continuous data mode. However, RSSI_IRQ may be mapped to IRQ1 instead of to IRQ0 in Continuous data mode.
T R C 1 0 5 R X F IF O
F ill
D C L K
D A T A
X
2 4 -B it (m in ) P r e a m b le (1 -0 ...)
1 to 4 B y te S ta rt P a tte rn
B y te 0
B y te 1
B y te 6 2
B y te 6 3
X
S ta rt P a tte rn
W r ite _ b y te
n F IF O E M P Y
F IF O F U L L
Figure 12
3.6 Transmitting in Continuous or Buffered Data Modes
The transmitter operates in Continuous data mode when the MCFG01_Mode [7..6] bits are set to 00. Bit clock
DCLK is available on pin IRQ1. Bits are clocked into the transmitter on the rising edge of this clock. Data must be
stable 2 µs before the rising edge of DCLK and must be held for 2 µs following the rising edge of this clock
(TSUDATA). To meet this requirement, data can be changed on the falling edge of DCLK. In FSK mode DCLK must
be used but is optional in OOK mode.
The transmitter operates in Buffered data mode when the MCFG01_Mode [5] bit is set to 1. Data to be transmitted is written to the 64-byte FIFO through the SPI interface. FIFO data is loaded byte-by-byte into a shift register
which then transfers the data bit-by-bit to the modulator. FIFO operation in transmit mode is similar to receive
mode. Transmission can start immediately after the first byte of data is written into the FIFO or when the FIFO is
full, as determined by the IRQCFG0E_Start_Full[4] bit setting. If the transmit FIFO is full, the interrupt signal
IRQCFG0D_ FIFOFULL[2] is asserted on pin IRQ1. If data is written into the FIFO while it is full, the flag
IRQCFG0D_FIFO_OVR[0] will be set to 1 and the previous FIFO contents will be overwritten. The IRQCFG0D_
FIFO_OVR[0] flag is cleared by writing a 1 to it. At the same time the contents of the FIFO are cleared. Once the
last data byte in the FIFO is loaded into the shift register driving the transmitter modulator, the flag IRQCFG0D_
nFIFOEMPY[1] is set to 0 on pin IRQ0. If new data is not written to the FIFO and the last bit has been transferred
to the modulator, the IRQCFG0E_TX_STOP[5] bit goes high as the modulator starts to send the last bit. The
transmitter must remain on one bit period after TX_STOP to transmit the last bit. If the transmitter is switched off
(switched to another mode), the transmission stops immediately even if there is still data in the shift register. In
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 17 of 67
TRC105 - 10/16/12
transmit mode the two interrupt signals are IRQ0 and IRQ1. IRQ1 is mapped to IRQCFG0D_FIFOFULL[2] signal
indicating that the transmission FIFO is full when IRQCFG0D_TX_IRQ1[3] is set to 0, or to IRQCFG0E_TX_
STOP[5] when IRQCFG0D_ TX_IRQ1[3] is set to 1. IRQ0 is mapped to the IRQCFG0D_nFIFOEMPY[1] signal.
This signal indicates the transmitter FIFO is empty and must be refilled with data to continue transmission.
3.7 IRQ0 and IRQ1 Mapping
Two TRC105 outputs are dedicated to host microcontroller interrupts or signaling. The interrupts are IRQ0 and
IRQ1 and each have selectable sources. Tables 10, 11, 12 and 13 below summarize the interrupt mapping options. These interrupts are especially useful in Continuous or Buffered data mode operation.
IRQCFG0D_RX_IRQ0
Data Mode
IRQ0
00
Continuous
Output
IRQ0 Interrupt Source
Start Pattern Detect
01
Continuous
Output
RSSI_IRQ
10
Continuous
Output
Start Pattern Detect
11
Continuous
Output
Start Pattern Detect
00
Buffered
Output
None (set to 0)
01
Buffered
Output
Write_byte
10
Buffered
Output
nFIFOEMPY
11
Buffered
Output
Start Pattern Detect
00
Packet
Output
Data_Rdy
01
Packet
Output
Write_byte
10
Packet
Output
11
Packet
Output
nFIFOEMPY
Node Address Match if
ADDRS_cmp is enabled
Start Pattern Detect if
ADDRS_cmp is disabled
Table 10
IRQCFG0D_RX_IRQ1
Data Mode
IRQ1
IRQ1 Interrupt Source
00
Continuous
Output
DCLK
01
Continuous
Output
DCLK
10
Continuous
Output
DCLK
11
Continuous
Output
DCLK
00
Buffered
Output
None (set to 0)
01
Buffered
Output
FIFOFULL
10
Buffered
Output
RSSI_IRQ
11
Buffered
Output
FIFO_Int_Rx
00
Packet
Output
CRC_OK
01
Packet
Output
FIFOFULL
10
Packet
Output
RSSI_IRQ
11
Packet
Output
FIFO_Int_Rx
Table 11
Tables 12 and 13 describe the interrupts available in transmit mode:
IRQCFG0D_TX_IRQ0
Data Mode
IRQ0
0
Continuous
Output
None (set to 0)
1
Continuous
Output
None (set to 0)
0
Buffered
Output
FIFO_thresh
1
Buffered
Output
nFIFOEMPY
0
Packet
Output
FIFO_thresh
1
Packet
Output
nFIFOEMPY
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
IRQ0 Interrupt Source
Technical support +1.800.704.6079
Page 18 of 67
TRC105 - 10/16/12
Table 12
IRQCFG0D_TX_IRQ1
Data Mode
IRQ1
0
Continuous
Output
DCLK
IRQ0 Interrupt Source
1
Continuous
Output
DCLK
0
Buffered
Output
FIFOFULL
1
Buffered
Output
TX_Stop
0
Packet
Output
FIFOFULL
1
Packet
Output
TX_Stop
Table 13
3.8 Buffered Clock Output
The buffered clock output is a signal derived from FXTAL. It can be used as a reference clock for the host microcontroller and is output on the CLKOUT pin. The OSCFG1B_Clkout_En[7] bit controls the CLKOUT pin. When this
bit is set to 1, CLKOUT is enabled, otherwise it is disabled. The output frequency of CLKOUT is defined by the
value of the OSCFG1B_Clk_freq[6..2] parameter which gives the frequency divider ratio applied to FXTAL. Refer
to Table 42 for programming details. Note: CLKOUT is disabled when the TRC105 is in sleep mode. If sleep
mode is used, the host microcontroller must have provisions to run from its own clock source.
3.9 Packet Data Mode
The TRC105 provides optional on-chip RX and TX packet handling features. These features ease the development of packet oriented wireless communication protocols and free the MCU resources for other tasks. The options include enabling protocols based on fixed and variable packet lengths, data scrambling, CRC checksum calculations and received packet filtering. All the programmable parameters of the Packet data mode are accessible
through the PKTCFG configuration registers of the device. The Packet data mode is enabled when the register bit
MCFG01_Mode[7..6 ] is set to 10 or 11.
The packet handler supports three types of packet formats: fixed length packets, variable length packets, and extended variable length packets. The PKTCFG1E_Pkt_mode[7] bit selects either the fixed or the variable length
packet formats.
3.9.1 Fixed Length Packet Mode
The fixed length packet mode is selected by setting the PKTCFG1E_Pkt_mode[7] bit to 0. In this mode the
length of the packet is set by the PKTCFG1C_Pkt_len[6..0] register up to the size of the FIFO which has been
selected.
The length stored in this register is the length of the payload which includes the message data bytes and optional
address byte. The fixed length packet format shown in Figure 13 is made up of the following fields:
1. Preamble
2. Start pattern (network address)
3. Node address byte (optional)
4. Data bytes
5. Two-byte CRC checksum (optional)
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 19 of 67
TRC105 - 10/16/12
F ix e d L e n g th P a c k e t F o r m a t
M a n c h e s te r E n c o d in g o r S c r a m b lin g A p p lie d to th e s e B y te s
P r e a m b le
1 to 4 B y te s
S ta rt P a tte rn
(N e tw o rk A d d re s s )
1 to 4 B y te s
O p tio n a l
N o d e
A d d re s s
B y te
C R C
2 B y te s
D a ta B y te s
P a y lo a d B y te s = P K T C F G 1 C _ P k t_ le n [6 ..0 ]
M a x im u m L e n g th = F IF O L e n g th
T h e P r e a m b le , S ta r t P a tte r n a n d C R C b y te s a r e a d d e d to th e p a c k e t b y th e T R C 1 0 3 d u r in g tr a n s m it a n d r e m o v e d fr o m
th e p a c k e t d u r in g r e c e iv e .
Figure 13
3.9.2 Variable Length Packet Mode
The variable length packet mode is selected by setting bit PKTCFG1E_Pkt_mode[7] to 1. The packet format
shown in Figure 14 is programmable and is made up of the following fields:
1. Preamble
2. Start pattern (network address)
3. Length byte
4. Node address byte (optional)
5. Data bytes
6. Two-byte CRC checksum (optional)
V a r ia b le L e n g th P a c k e t F o r m a t
M a n c h e s te r E n c o d in g o r S c r a m b lin g A p p lie d to th e s e B y te s
P r e a m b le
1 to 4 B y te s
S ta rt P a tte rn
(N e tw o rk A d d re s s )
1 to 4 B y te s
O p tio n a l
N o d e
A d d re s s
B y te
L e n g th
B y te
M a x im u m
D a ta B y te s
P a y lo a d B y te s = F IF O
C R C
2 B y te s
L e n g th
T h e P r e a m b le , S ta r t P a tte r n a n d C R C b y te s a r e a d d e d to th e p a c k e t b y th e T R C 1 0 3 d u r in g tr a n s m it a n d r e m o v e d fr o m
th e p a c k e t d u r in g r e c e iv e .
Figure 14
In variable length packet mode, the length of the rest of the payload is given by the first byte written to the FIFO.
The length byte itself is not included in this count. The PKTCFG1C_Pkt_len[6..0] parameter is used to set the
maximum received payload length allowed. Any received packet having a value in the length byte greater than
this maximum is discarded. The variable length packet format accommodates payloads, including the length byte,
up to the length of the FIFO.
3.9.3 Extended Variable Length Packet Mode
The extended variable length packet mode is selected by setting bit PKTCFG1E_Pkt_mode[7] to 1 and setting
PKTCFG1C_Pkt_len[6..0] to a value between 65 and 127. The packet format shown in Figure 15 is programmable and is made up of the following fields:
1. Preamble
2. Start pattern (network address)
3. Length byte
4. Node address byte (optional)
5. Data bytes
6. Two-byte CRC checksum (optional)
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 20 of 67
TRC105 - 10/16/12
E x te n d e d V a r ia b le L e n g th P a c k e t F o r m a t, 6 5 to 1 2 7 B y te s
M a n c h e s te r E n c o d in g o r S c r a m b lin g A p p lie d to th e s e B y te s
P r e a m b le
1 to 4 B y te s
S ta rt P a tte rn
(N e tw o rk A d d re s s )
1 to 4 B y te s
L e n g th
B y te
O p tio n a l
N o d e
A d d re s s
B y te
M a x im u m
D a ta B y te s
C R C
2 B y te s
P a y lo a d B y te s = P K T C F G 1 C _ P k t_ le n [6 ..0 ]
T h e P r e a m b le , S ta r t P a tte r n a n d C R C b y te s a r e a d d e d to th e p a c k e t b y th e T R C 1 0 3 d u r in g tr a n s m it a n d r e m o v e d fr o m
th e p a c k e t d u r in g r e c e iv e .
Figure 15
In extended variable length packet mode, the length of the rest of the payload is given by the first byte written to
the FIFO. The length byte itself is not included in this count. There are a number of ways to use the extended variable length packet capability. The most common way is outlined below:
1. Set PKTCFG1C_Pkt_len[6..0] to a value between 65 (0x41) and 127 (0x7F). This sets the maximum allowed
payload in extended packet mode. Any received packet having a value in the length byte greater than this maximum is discarded.
2. Set PKTCFG1E_Pkt_mode[7] to 1 for variable length packet mode operation. Set the PKTCFG1E_ Preamb_len[6..5] bits to 10 or 11 for a 3 or 4 byte preamble. Set the PKTCFG1E_CRC_En[3] bit to 1 to enable CRC
processing. Set the PKTCFG1E_Pkt_ADDRS_cmp[2..1] bits as required. Clear the PKTCFG1E_ CRC_stat[0]
bit by writing a 1 to it.
3. Set MCFG0C_FIFO_depth[7..6] bits to 11 for a 64 byte FIFO length.
4. Set the MCFG0C_FIFO_thresh[5..0] to approximately 31(0x1F). This sets the threshold to 32, near the mid
point of the FIFO. Provided the host microcontroller is relatively fast (usual case), this setting can be used for
monitoring the FIFO in both transmit and receive. If the host microcontroller is relatively slow, set the threshold to
a value lower than 31 for receive, and higher than 31 for transmit.
5. Set the IRQCFG0D_RX_IRQ1[5..4] bits to 11. This maps FIFO_Int_Rx interrupt to IRQ1, which trips when the
number of received bytes in the FIFO is equal to or greater than the value in MCFG05_FIFO_thresh. IRQ1 will
then signal received bytes must be retrieved. If received bytes are not retrieved before the FIFO completely fills,
data will be lost.
6. Set the IRQCFG0D_TX_IRQ0[3] bit to 0. This causes a transmission to start when the number of transmit
bytes in the FIFO is equal to or greater than the value in MCFG0C_FIFO_thresh. Also, the FIFO_Int_Tx interrupt
is mapped to IRQ0 in transmit mode, and is set when the number of bytes in the FIFO is equal to or less than the
value in MCFG0C_FIFO_thresh. IRQ0 will then signal more bytes can be added to the FIFO. If more message
bytes are not added in time, the transmission will cease prematurely and data will be lost. Likewise, if more bytes
are sent to the FIFO than it has room for, data will be lost.
7. When receiving an extended variable length packet, monitor IRQ1. When IRQ1 trips, clock out some of the received bytes from the FIFO (leave at least one byte in the FIFO). Repeat the partial packet retrieval each time
IRQ1 triggers. The first byte received is the number of message bytes, and can be used to tell when the last message byte has been retrieved. When it is determined that the remaining message bytes will not overflow the FIFO,
the IRQCFG0D_RX_IRQ1[5..4] bits can be set to 00, which maps CRC_OK to IRQ1. After the CRC is checked,
the final bytes can be read from the FIFO and the IRQCFG0D_RX_IRQ1[5..4] bits can be reset to 11 to track
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 21 of 67
TRC105 - 10/16/12
FIFO_Int_Rx when the next packet is received. Note that CRC mapping to IRQ1 is not required if the CRC state is
read from the PKTCFG1E_ CRC_stat[0] bit prior to reading the final FIFO bytes.
8. When transmitting an extended variable length packet, begin filling the FIFO until IRQ0 trips, indicating the
FIFO is half full. Add up to 32 bytes to the FIFO (64 - (MCFG05_ FIFO_thresh +1)) when IRQ0 resets. Repeat the
partial packet loading each time IRQ0 resets until all bytes to be transmitted have been clocked in. The
IRQCFG0D_TX_IRQ1[3] bit can then be set to 1, which allows the TX_STOP event to be mapped to IRQ1.
TX_STOP signals the last bit to be transmitted has been transferred the modulator. Allow one bit period for this bit
to be transmitted before switching out of transmit mode.
3.9.4 Packet Payload Processing in Transmit and Receive
The TRC105 packet handler constructs transmit packets using the payload in the FIFO. In receive, it processes
the packets and extracts the payload to the FIFO. Packet processing in transmit and receive are detailed below.
For transmit, the packet handler adds the following fields and processing to the payload in the FIFO:
1. One automatic preamble byte
2. One to four additional preamble bytes, programmable and usually set to 3 or 4 bytes
3. One to four start pattern bytes, programmable and usually set to at least 2 bytes
4. Optional CRC checksum calculated over the FIFO payload and appending to the end of the packet
5. Optional Manchester encoding or DC-balanced scrambling
The payload in the FIFO may contain one or both of the following optional fields:
1. A length byte if the variable packet length mode is selected
2. A node address byte
If the FIFO is filled while transmit mode is enabled, and if IRQCFG0E_Start_Full[4] is set to 1, the modulator
waits until the first byte is written into the FIFO, then it starts sending the programmed preamble bytes followed by
the start pattern and the user payload. If IRQCFG0E_Start_Full[4 ] is set to 0 in the same conditions, the modulator waits until the number of bytes written in the FIFO is equal to the number defined in the register MCFG05_
FIFO_thresh[5..0]. Note that the transmitter automatically sends preamble bytes in addition the number programmed while in transmit mode and waiting for the FIFO to receive the required number of bytes to start data
transmission. Data to be transmitted can also be written into the FIFO during standby mode. In this case, the data
is automatically transmitted when the transmit mode is enabled and the transmitter reaches its steady state.
If CRC is enabled, the CRC checksum is calculated over the payload bytes. This 16-bit checksum is sent after the
bytes in the FIFO. If CRC is enabled, the TX_STOP bit is set when the last CRC bit is transferred to the TX modulator. If CRC is not enabled, the TX_STOP bit is set when the last bit from the FIFO is transferred to the TX modulator. Note that the transmitter must remain on one bit period after the TX_STOP bit is set while the last bit is being transmitted. If the transmitter remains on following the transmission of the last bit after TX_STOP is set, the
transmitter will send preamble bytes. If Manchester encoding or scrambling is enabled, all data except the preamble and start pattern is encoded or scrambled before transmission. Note that the length byte in the FIFO determines the length of the packet to be sent and the PKTCFG1C_Pkt_len[6..0] parameter is not used in transmit.
In receive, the packet handler retrieves the payload by performing the following steps:
1. Data and clock recovery synchronization to the preamble
2. Start pattern detection
3. Optional address byte check
4. Error detection through CRC
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 22 of 67
TRC105 - 10/16/12
When receive mode is enabled, the demodulator detects the preamble followed by the start pattern. If fixed length
packet format is enabled, then the number of bytes received as the payload is given by the PKTCFG1C_Pkt_
len[6..0] parameter. In variable length and extended variable length packet modes, the first byte received after
the start pattern is interpreted as the length of the balance of the payload. An internal length counter is initialized
to this length. The PKTCFG1C_Pkt_len[6..0] register must be set to a value which is equal to or greater than the
maximum expected length byte value of the received packet. If the length byte value of a received packet is
greater than the value in the PKTCFG1C_ Pkt_len[6..0] register, the packet is discarded. Otherwise the packet
payload begins loading into the FIFO.
If address match is enabled, the second byte received in a variable length mode or the first byte in the fixed length
mode is interpreted as the node address. If this address matches the byte in PKTCFG1D_Node_Addrs[7..0],
reception of the packet continues, otherwise it is stopped. A CRC check is performed if PKTCFG1E_CRC_
En[3] is set to 1. If the CRC check is successful, a 1 is loaded in the PKTCFG1E_CRC_stat[0] bit, and CRC_OK
and Dat_Rdy interrupts are simultaneously generated on IRQ1 and IRQ0 respectively. This signals that the payload or balance of the payload can be read from the FIFO. In receive mode, address match, Dat_Rdy, and
CRC_OK interrupts and the CRC_stat bit are reset when the last byte in the FIFO is read. Note the FIFO can be
read in standby mode by setting PGCFG1F_ RnW_FIFO[6] bit to 1. In standby, reading the last FIFO byte does
not clear CRC_OK and the CRC_stat bit. They are reset once the TRC103 is put in receive mode again and a
start pattern is detected.
If the CRC check fails, the FIFO is cleared and no interrupts are generated. This action can be overridden by setting PGCFG1F_CRCclr_auto[7] to 1, which forces a Data_Rdy interrupt and preserves the payload in the FIFO
even if the CRC fails.
If address checking is enabled, the second byte received in a variable length mode or the first byte in the fixed
length mode is interpreted as the node address. If this address matches the byte in PKTCFG1D_Node_
Addrs[7..0], reception of the packet continues, otherwise it is stopped. A CRC check is performed if PKTCFG1E_
CRC_En[3] is set to 1. If the CRC check is successful, a 1 is loaded in the PKTCFG1E_CRC_stat[0] bit, and
CRC_OK and Dat_Rdy interrupts are simultaneously generated on IRQ1 and IRQ0 respectively, signaling the
payload or balance of the payload can be read from the FIFO. Note the FIFO can be read in standby mode by
setting PGCFG1F_ RnW_FIFO[6] bit to 1. If the CRC check fails, the FIFO is cleared and no interrupts are generated. This action can be overridden by setting PGCFG1F_CRCclr_auto[7] to 1, which forces a Data_Rdy interrupt and preserves the payload in the FIFO even if the CRC fails.
3.9.5 Packet Filtering
Received packets can be filtered based on two criteria: length filtering and address filtering. In variable length or
extended variable length packet formats, PKTCFG1C_Pkt_len[6..0] stores the maximum packet length permitted.
If the received packet length is greater than this value, then the packet is discarded. Node address filtering is enabled by setting parameter PKTCFG1E_Addrs_cmp[2..1] to any value other than 00, i.e., 01, 10 or 11. These
settings enable the following three options:
PKTCFG1E_Addrs_cmp[2..1] = 01: This configuration activates the address filtering function on the packet
handler and the received address byte is compared with the address in the PKTCFG1D_Node_Addrs[7..0] register. If both address bytes are the same, the received packet is for the current destination and is stored in FIFO.
Otherwise it is discarded. An interrupt can also be generated on IRQ0 if the address comparison is successful.
PKTCFG1E_Addrs_cmp[2..1] = 10: In this configuration the received address is compared to both the
PKTCFG1D_Node_Addrs[7..0] register and constant 0x00. If the received address byte matches either value,
the packet is accepted. An interrupt can also be generated on IRQ0 if the address comparison is successful. The
0x00 address is useful for sending broadcast packets.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 23 of 67
TRC105 - 10/16/12
PKTCFG1E_Addrs_cmp[2..1] = 11: In this configuration the packet is accepted if the received address matches
either the PKTCFG1D_Node_addrs[7..0] register, 0x00 or 0xFF. An interrupt can also be generated on IRQ0 if
the address comparison is successful. The 0x00 and 0xFF addresses are useful for sending two types of broadcast packets.
3.9.6 Cyclic Redundancy Check
CRC check is enabled by setting the PKTCFG1E_CRC_En[3] bit to 1. A 16-bit CRC checksum is calculated on
the payload part of the packet and is appended to the end of the transmitted message. The CRC checksum is
calculated on the received payload and compared to the transmitted CRC. The result of the comparison is stored
in the PKTCFG1E_CRC_stat[0] bit and an interrupt can also be generated on IRQ1. The CRC is based on the
CCITT polynomial as shown in Figure 16. The CRC also detects errors due to leading and trailing zeros.
T R C 1 0 5 C R C Im p le m e n ta tio n
X 16 + X 12 + X 5 + 1
D A T A
IN P U T
X O R
S R 1 5
S R 1 2
X O R
S R 1 1
S R 5
X O R
S R 4
S R 0
A ll 1 6 s h ift r e g is te r s p r e s e t to 1 b e fo r e e a c h C R C c a lc u la tio n
Figure 16
3.9.7 Manchester Encoding
Manchester encoding is enabled by setting the PKTCFG1C_Man_en[7] bit to 1, and can only be used in Packet
data mode. Figure 17 illustrates Manchester encoding. NRZ data is converted to Manchester by encoding 1 bits
as 10 chip sequences, and 0 bits as 01 chip sequences. Manchester encoding guarantees DC-balance and frequent data transitions in the encoded data. Note the maximum Manchester chip rate corresponds to the maximum
bit rate given in the specifications in Table 52.
T R C 1 0 5 M a n c h e s te r D a ta E n c o d in g
C h ip
C lo c k
N R Z
D a ta
M a n c h e s te r
E n c o d e d
D a ta
Figure17
In transmit, Manchester encoding is applied only to the payload and CRC parts of the packet. The receiver decodes the payload and CRC before performing other packet processing tasks.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 24 of 67
TRC105 - 10/16/12
3.9.8 DC-Balanced Scrambling
A payload may contain long sequences of 1 or 0 bits. These sequences would introduce DC biases in the transmitted signal, causing a non-uniform power distribution spectrum. These sequences would also degrade the performance of the demodulation and data and clock recovery functions in the receiver. System performance can be
enhanced if the payload bits are randomized to reduce DC biases and increase the number of bit transitions.
As discussed above, DC-balanced data can be obtained by using Manchester encoding, which ensures that there
are no more than two consecutive 1’s or 0’s in the transmitted data. However, this reduces the effective bit-rate of
the system because it doubles the amount of data to be transmitted.
Another technique called scrambling (whitening) is widely used for randomizing data before radio transmission.
The data is scrambled using a random sequence on the transmit side and then descrambled on the receive side
using the same sequence.
The TRC105 packet handler provides a mechanism for scrambling the packet payload. A 9-bit LFSR is used to
generate a random sequence. The payload and the 16-bit CRC checksum are XOR’d with this random sequence
as shown in Figure 18. The data is descrambled on the receiver side by XORing with the same random sequence. The scrambling/descrambling process is enabled by setting the PKTCFG1E_Scrmb_En[4] bit to 1.
T R C 1 0 5 D a ta S c r a m b lin g Im p le m e n ta tio n
X 9 + X 5 + 1
X O R
S R 8
S R 5
S R 4
S R 0
D A T A
A ll 9 s h ift r e g is te r s p r e s e t to 1 b e fo r e e a c h s c r a m b lin g ( D C
X O R
S C R A M B L E D
D A T A O U T P U T
IN P U T
b a la n c in g ) c a lc u la tio n
Figure 18
3.10 SPI Configuration Interface
The TRC105 contains two SPI-compatible interfaces, one to read and write the configuration registers, the other
to read and write FIFO data. Both interfaces are configured in slave mode and share the same pins: SDO (SPI
Slave Data Out), SDI (SPI Slave Data In), and SCK (Serial Clock). Two pins are provided to select the SPI connection. The nSS_CONFIG pin allows access to the configuration registers and the nSS_DATA pin allows access
to the FIFO. Figure 19 shows a typical connection between a host microcontroller and the SPI interface.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 25 of 67
TRC105 - 10/16/12
T R C 1 0 5 - M ic r o c o n tr o lle r S ig n a l C o n n e c tio n s
IR Q 0
IR Q 1 /D C L K
D A T A
P L L _ L O C K
H o s t
M ic r o c o n tr o lle r
T R C 1 0 5
S C K
S D I
S D O
n S S _ D A T A
n S S _ C O N F IG
Figure 19
A byte transmission can be seen as a rotate operation between the value stored in an 8-bit shift register in the
master device (host microcontroller) and the value stored in an 8-bit shift register in the transceiver. The SCK line
is used to synchronize both SPI bit transfers. Data is transferred full-duplex from master to slave through the SDI
line and from slave to master through the SDO line. The most significant bit is always sent first. In both directions
the rising SCK edge is used to sample a bit, and the falling SCK edge shifts the bits through the shift register.
The nSS_CONFIG or nSS_DATA signals are asserted by the master device and should remain low during a byte
transmission. The transmission is synchronized by these nSS_CONFIG or nSS_DATA signals. While the
nSS_CONFIG or nSS_DATA is set to 1, the counters controlling transmission are reset. Reception starts with the
first clock cycle after the falling edge of nSS_CONFIG or nSS_DATA. If either signal goes high during a byte
transmission the counters are reset and the byte must be retransmitted.
The configuration interface is selected if nSS_CONFIG is low even if the TRC105 is in buffered mode and
nSS_DATA is low (nSS_CONFIG has priority). To configure the transceiver two bytes are required. The first byte
contains a 0 start bit, R/W information (1 = read, 0 = write), 5 bits for the address of the register and a 0 stop bit.
The second byte contains the data to be sent in write mode or the new address to read from in read mode.
S in g le B y te C o n fig u r a tio n R e g is te r W r ite
n S S _ C O N F IG
S C K
S D I
X
S T A R T
R /W
A 4
A 3
A 2
A 1
A 0
S T O P
D 7
D 6
D 5
R e g is te r A d d r e s s
S D O
H i-Z
X
X
X
X
X
D 4
X
N e w
X
X
D 7
D 6
D 5
D 3
D 2
D 1
D 0
X
D 2
D 1
D 0
H i-Z
R e g is te r V a lu e
D 4
D 3
O ld R e g is te r V a lu e
Figure 20
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 26 of 67
TRC105 - 10/16/12
Figure 20 shows the timing diagram for a single byte write sequence to the TRC105 through the SPI configuration
interface. Note that nSS_CONFIG must remain low during the transmission of the two bytes (address and data). If
it goes high after the first byte, then the next byte will be considered as an address byte. When writing to more
than one register successively, nSS_CONFIG does not need to have a high-to-low transition between two write
sequences. The bytes are alternatively considered as an address byte followed by a data byte.
The read sequence through the SPI configuration interface is similar to the write sequence. The host microcontroller sends the address during the first SPI communication and then reads the data during a second SPI communication. Note that 0 bits can be input to the SDI during the second SPI communication for a single byte read.
Figure 21 shows the timing diagram for a single byte read sequence from the TRC105 through the SPI.
S in g le B y te C o n fig u r a tio n R e g is te r R e a d
n S S _ C O N F IG
S C K
S D I
X
S T A R T
R /W
A 4
A 3
A 2
A 1
A 0
X
X
X
R e g is te r A d d r e s s
S D O
H i-Z
X
X
X
X
X
X
D 7
D 6
D 5
D 4
D 3
D 2
D 1
D 0
H i-Z
R e g is te r V a lu e
Figure 21
M u lti-b y te C o n fig u r a tio n R e g is te r R e a d
n S S _ C O N F IG
S C K
S D I
X
S T A R T
R /W
A 4
A 3
A 2
A 1
A 0
X
S T A R T
R /W
A 4
F ir s t R e g is te r A d d r e s s
S D O
H i-Z
X
X
X
X
X
X
A 3
A 2
A 1
A 0
X
S T A R T
R /W
A 4
X
S e c o n d R e g is te r A d d r e s s
X
D 7
D 6
D 5
D 4
D 3
D 2
F ir s t R e g is te r V a lu e
A 3
A 2
A 1
A 0
S T A R T
D 1
D 0
T h ir d R e g is te r A d d r e s s
D 1
D 0
D 7
D 6
D 5
D 4
D 3
D 2
S e c o n d R e g is te r V a lu e
Figure 22
Multiple configuration register reads are also possible by sending a series of register addresses into the SPI port,
as shown in Figure 22.
3.11 SPI Data FIFO Interface
When the transceiver is used in Buffered or Packet data mode, data is written to and read from the FIFO through
the SPI interface. Two interrupts, IRQ0 and IRQ1, are used to manage the transfer procedure.
When the transceiver is operating in Buffered or Packet data mode, the FIFO interface is selected when
nSS_DATA is set to 0 and nSS_CONFIG is set to 1. SPI operations with the FIFO are similar to operations with
the configuration registers with two important exceptions. First, no addresses are used with the FIFO, only data
bytes are exchanged. Second, nSS_DATA must be toggled high and back low between data bytes when writing
to the FIFO or reading from the FIFO. Toggling nSS_DATA indexes the access pointer to each byte in the FIFO in
lieu of using explicit addressing. Figure 23 shows the timing diagram for a multiple-byte write sequence to the
TRC105 during transmit, and Figure 24 shows the timing for a multi-byte read sequence.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 27 of 67
TRC105 - 10/16/12
T R C 1 0 5 D a ta W r ite to F IF O
n S S _ D A T A
S C K
S D I
X
D 7
D 6
D 5
D 4
D 3
D 2
D 1
D 0
X
D 7
D 6
D 5
S D O
H i-Z
X
X
X
X
X
D 4
D 3
D 2
D 1
D 0
X
X
X
H i-Z
H i-Z
S e c o n d B y te W r itte n
F ir s t B y te W r itte n
X
X
X
H i-Z
X
X
X
X
X
Figure 23
T R C 1 0 5 D a ta R e a d fro m
F IF O
n S S _ D A T A
S C K
S D I
X
X
X
X
S D O
H i-Z
D 7
D 6
D 5
X
X
X
X
X
X
X
X
X
D 4
D 3
D 2
D 1
D 0
H i-Z
D 7
D 6
D 5
X
X
X
X
X
D 4
D 3
D 2
D 1
D 0
S e c o n d B y te R e a d
F ir s t B y te R e a d
Figure 24
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 28 of 67
TRC105 - 10/16/12
4.0 Configuration Register Memory Map
Register names are based on the function name and address location for easy reference. The page 0 (default)
register memory map is shown in Table 14 below. The two configuration registers for low battery detection are
located in the page 1 register memory map. See Tables 47 and 48 for details of these registers.
Hex
Address
Function
Name
0x1F
PGCFG1F
PKTCFG1E
PKTCFG1D
PKTCFG1C
OSCFG1B
TXCFG1A
SYNCFG19
SYNCFG18
SYNCFG17
SYNCFG16
RXCFG15
RXCFG14
RXCFG13
RXCFG12
RXCFG11
RXCFG10
IRQCFG0F
IRQCFG0E
IRQCFG0D
IRQCFG0C
MCFG0B
MCFG0A
MCFG09
MCFG08
MCFG07
MCFG06
MCFG05
MCFG04
MCFG03
MCFG02
MCFG01
MCFG00
0x1C
0x1B
0x1A
0x16
0x10
0x0C
0x00
Table 14
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 29 of 67
TRC105 - 10/16/12
4.1 Main Configuration Registers (MCFG)
Power-up default settings are shown in bold:
0x00 - MCFG00 [default 0x2F]
Name
Bits
R/W
Description
Transceiver chip mode:
000 → Sleep
001 → Standby
Chip_Mode
7,6,5
r/w
010 → Synthesizer
011 → Receive
100 → Transmit
101, 100, 111 → not used
Frequency band:
000 → 300-330 MHz
001 → 330-365 MHz
Band
4,3,2
r/w
010 → 365-400 MHz
011 → 400-440 MHz
100 → 440-470 MHz
101 → 470-510 MHz
110, 111 → not used
Frequency subband:
st
00 → 1 (lowest) quarter of selected band
Subband
1,0
r/w
nd
01 → 2 quarter of selected band
rd
10 → 3 quarter of selected band
th
11 → 4 (highest) quarter of selected band
Table 15
0x01 - MCFG01 [default 0x24]
Name
Bits
R/W
Description
Data mode:
Mode
7,6
r/w
00 → Continuous
01 → Buffered
10, 11→ Packet
TX/RX modulation:
00 → Reset
FSK_OOK
5,4
r/w
01→ OOK
10 → FSK
11 → not used
RX OOK threshold mode:
00 → Fixed Threshold
RX_OOK
3,2
r/w
01 → Peak Mode
10 → AVG Mode
11 → not used
Gain (AGC) on IF chain:
00 → maximum IF gain
IF_Gain
1,0
r/w
01 → -4.5 dB below maximum
10 → -9 dB below maximum
11 → -13.5 dB below maximum
Table 16
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 30 of 67
TRC105 - 10/16/12
0x02 - MCFG02 [default 0x03]
Name
Bits
R/W
Description
Frequency deviation:
Freq_Dev
7..0
FDEV = FXTAL/(32·(R+1)) where R is the Freq_Dev register value, FDEV and FXTAL are in kHz,
r/w
0 ≤ R ≤ 255
Freq_Dev default = 3, FDEV = ±100 kHz for FXTAL = 12,800 kHz
Table 17
0x03 - MCFG03 [default 0x07]
Name
Bits
R/W
7..0
r/w
Description
BR = FXTAL/(2*(C+1)*(D + 1)), where C and D are the bit rate parameters, and bit rate BR and
Bit_Rate_C
FXTAL are in kHz, 0 ≤ C ≤ 255, D = 31 for standard applications
Bit_Rate_C default = 7, BR = 25 kb/s for FXTAL = 12,800 kHz
Table 18
0x04 - MCFG04 [default 0x1F]
Name
Bits
R/W
7..0
r/w
Description
BR = FXTAL/(2*(C+1)*(D + 1)), where C and D are the bit rate parameters, and bit rate BR and
Bit_Rate_D
FXTAL are in kHz, 15 ≤ D ≤ 255. The default value of 31 is suitable for most applications.
Bit_Rate_D default = 31, BR = 25 kb/s for FXTAL = 12,800 kHz
Table 19
0x05 - MCFG05 [default 0xC6]
Name
Bits
R/W
Description
Rise/fall time control of Power Amplifier in OOK mode:
00 → 3 µs
PA_Ramp
7,6
r/w
01 →8.5 µs
10 → 15 µs
11 → 23 µs
Enables receiver low power mode by reducing LNA current
RX_Low_Pwr
5
r/w
4,3
r/w
0 → Low power mode off
1 → Low power mode on (suitable for most applications)
Reserved
Not used
VCO trimming:
00 → 0 mV
Trim
2,1
r/w
01 → 60 mV
10 → 120 mV
11 → 180 mV
Selection between two RF frequencies as defined by SynthRx, SynthPx, and SynthSx registers:
RF_Freq
0
r/w
0 → Frequency 1
1 → Frequency 2
Table 20
0x06 - MCFG06 [default 0x6B]
Name
Bits
R/W
SynthR1
7..0
r/w
Description
RF frequency 1, R counter
R1 = 0x6B (01101011) for 434 MHz
Table 21
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 31 of 67
TRC105 - 10/16/12
0x07 - MCFG07 [default 0x2A]
Name
Bits
R/W
SynthP1
7..0
r/w
Description
RF frequency 1, P counter
P1 = 0x2A (00101010) for 434 MHz
Table 22
0x08 - MCFG08 [default 0x1E]
Name
Bits
R/W
SynthS1
7..0
r/w
Description
RF frequency 1, S counter
S1 = 0x1E (00011110) for 434 MHz
Table 23
0x09– MCFG09 [default 0x77]
Name
Bits
R/W
SynthR2
7..0
r/w
Description
RF frequency 2, R counter
R2 = 0x77 (01110111b) for 435 MHz
Table 24
0x0A - MCFG0A [default 0x2F]
Name
Bits
R/W
SynthP2
7..0
r/w
Description
RF frequency 2, P counter
P2 = 0x2F (00101111b) for 435 MHz
Table 25
0x0B - MCFG0B [default 0x19]
Name
Bits
R/W
SynthS2
7..0
r/w
Description
RF frequency 2, S counter
S2 = 0x19 (00011001b) for 435 MHz
Table 26
0x0C - MCFG0C [default 0x0F]
Name
Bits
R/W
Description
Configures the size of the FIFO:
00 → 16 bytes
FIFO_depth
7,6
r/w
01 → 32 bytes
10 → 48 bytes
11 → 64 bytes
Number of bytes to be written in the FIFO to activate the FIFO_Int_Tx and FIFO_Int_Rx interrupts.
FIFO_thresh
5..0
r/w
Number of bytes = B + 1, where B is the register value.
FIFO_thresh default = 15, Number of bytes = 16
Table 27
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 32 of 67
TRC105 - 10/16/12
4.2 Interrupt Configuration Registers (IRQCFG)
0x0D - IRQCFG0D [default 0x00]
Name
Bits
R/W
Description
IRQ0 source in receive mode:
Continuous data mode 00 → IRQ0 mapped to pattern signal
01 → IRQ0 mapped to RSSI_IRQ
10,11 → IRQ0 mapped to start pattern detect
Buffered data mode 00 → IRQ0 set to 0
RX_IRQ0
7,6
r/w
01 → IRQ0 mapped to Write_byte
10 → IRQ0 mapped to nFIFOEMPY (also in Standby mode)
11 → IRQ0 mapped to start pattern detect
Packet data mode 00 → IRQ0 mapped to Data_Rdy signal
01 → IRQ0 mapped to Write_byte
10 → IRQ0 mapped to nFIFOEMPY (also in Standby mode)
11 → IRQ0 mapped to Node Address Match if ADDRS_cmp is enabled
11 → IRQ0 mapped to Start Pattern Detect if ADDRS_cmp is not enabled
IRQ1 source in receive mode.
Continuous data mode 00 → IRQ1 mapped to DCLK signal
01,10,11 → IRQ1 mapped to DCLK
Buffered data mode 00 → IRQ1 set to 0
RX_IRQ1
5,4
r/w
01 → IRQ1 mapped to FIFOFULL
10 → IRQ1 mapped to RSSI_IRQ
11 → IRQ1 mapped to FIFO_Int_Rx (also in Standby mode)
Packet data mode 00 → IRQ1 mapped to CRC_OK
01 → IRQ1 mapped to FIFOFULL (also in Standby mode)
10 → IRQ1 mapped to RSSI_IRQ
11 → IRQ1 mapped to FIFO_Int_Rx (also in Standby mode)
IRQ0 source in transmit mode:
Continuous data mode -
TX_IRQ0
3
r/w
0,1 → IRQ0 set to 0
Buffered or Packet data modes 0 → IRQ0 mapped to FIFO_thresh (transmission starts when IRQ0 switches high)
1 → IRQ0 is mapped to nFIFOEMPY (transmission starts when IRQ0 switches high)
IRQ1 source in transmit mode.
Continuous data mode -
TX_IRQ1
2
r
0, 1→ IRQ_1 mapped to DCLK
Buffered or Packet data modes 0 → IRQ1 mapped to FIFOFULL
1 → IRQ1 is mapped to TX_Stop
FIFOFULL
1
r
FIFO full (IRQ source)
nFIFOEMPY
0
r
low when FIFO empty (IRQ source).
Table 28
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 33 of 67
TRC105 - 10/16/12
0x0E - IRQCFG0E [default 0x01]
Name
Bits
R/W
7
r/w
Description
FIFO fill mode selection:
Start_Fill
0 → FIFO starts filling when start pattern is recognized
1 → FIFO fills as long as Start_Det is 1
Start of FIFO fill:
If Start_Fill = 0, goes high when start pattern recognized. Write a 1 to reset the start pattern
Start_Det
6
r/w/c
recognition.
If Start_Fill = 1
0 → Stop filling FIFO
1 → Start filling FIFO
Transmit state:
TX_Stop
5
r
0 → Transferring bits to the TX modulator
1 → Last bit transferred to the TX modulator
FIFO overflow:
FIFO_OVR
4
r/w/c
In Buffered data mode, writing a 1 to this bit clears the FIFO.
In Packet data mode, writing a 1 to this bit clears the FIFO and allows a new packet to be transmitted
or received immediately.
Enables SIG_DETECT when RSSI_thld is tripped:
RSSI_Int
3
r/w
0 → Disable interrupt
1→ Enable interrupt
Detects a signal above the RSSI_thld:
SIG_DETECT
2
r/w/c
0 → Signal lower than threshold
1 → Signal equal or greater than the RSSI_thld level
This bit latches high and must be cleared by writing a 1 to its location.
Detects the PLL lock status:
PLL_LOCK_ST
1
r/w/c
0 → PLL not locked
1 → PLL locked
This bit latches high each time the PLL locks and must be cleared by writing a 1 to its location.
Enables the PLL_LOCK signal on Pin 23
PLL_LOCK_EN
0
r/w
0 → PLL_LOCK signal disabled, Pin 23 set high
1 → PLL_LOCK signal enabled
Table 29
0x0F - IRQCFG0F [default 0x00]
Name
RSSI_thld(7..0)
Bits
7..0
R/W
r/w
Description
RSSI threshold level for interrupt.
RSSI_thld default is 0x00
Table 30
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 34 of 67
TRC105 - 10/16/12
4.3 Receiver Configuration Registers (RXCFG)
0x10 - RXCFG10 [default 0xA3]
Name
Bits
R/W
Description
Bandwidth of the low-pass filter.
0000 → 65 kHz
0001 → 82 kHz
0010 → 109 kHz
0011 → 137 kHz
0100 → 157 kHz
0101 → 184 kHz
0110 → 211 kHz
LP_filt(7..4)
7,6,5,4
r/w
0111 → 234 kHz
1000 → 262 kHz
1001 → 321 kHz
1010 → 378 kHz
1011 → 414 kHz
1100 → 458 kHz
1101 → 514 kHz
1110 → 676 kHz
1111 → 987 kHz
Cutoff frequency of the receiver FSK Butterworth low-pass filters:
FCBW = 200*(FXTAL/12800)*((J + 1)/8), where FCBW is the 3 dB cutoff frequency of the Butterworth filters in
kHz, and J is the integer value of BW_filt with a range of 0 to 15.
or
BW_filt(3..0)
3,2,1,0
r/w
Upper cutoff frequency of the OOK polyphase band-pass filters:
FCPP = FOPP + 200*(FXTAL/12800)*((J + 1)/8), where FCPP is the upper cutoff frequency of polyphase filters in
kHz , FOPP is the center frequency of the OOK polyphase filters in kHz (see RXCFG11 below), FXTAL is the
crystal frequency in kHz, and J is the integer value of BW_filt with the usable range of 0 to 1.
BW_filt default = 0011b, FCBW = 100 kHz for a 12,800 kHz crystal
Table 31
0x11 - RXCFG11 [default 0x38]
Name
Bits
R/W
Description
Center frequency of the polyphase filter:
Polyfilt(7..4)
7,6,5,4
r/w
FOPP = 200*(FXTAL/12800)*((L + 1)/8), where FOPP is the center frequency of the OOK polyphase filter in
kHz, FXTAL is the crystal frequency in kHz, and L is the integer value of Polyfilt.
Polyfilt default = 0011b, FOPP = 100 kHz for a 12,800 kHz crystal
Power Amp Step regulation mode:
PA_reg
3
r/w
0 → Regulation disabled
1 → Regulation enabled
-
2,1,0
Not used
Table 32
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 35 of 67
TRC105 - 10/16/12
0x12 - RXCFG12 [default 0x18]
Name
Bits
R/W
7
r/w
Description
Polyphase filter enable:
Polyfilt_En
0 → Polyphase filter disabled
1 → Polyphase filter enabled
Data and clock recovery enable:
DCLK_Dis
6
r/w
0 → Enabled
1 → Disabled
Start pattern detect (recognition) enable:
Recog
5
r/w
0 → Disabled
1 → Enabled
Start pattern size:
00 → 1 byte (SYNCGF16 byte)
Pat_sz
4,3
r/w
01 → 2 bytes (SYNCGF16 and SYNCGF17 bytes)
10 → 3 bytes (SYNCGF16, SYNCGF17 and SYNCGF18 bytes)
11 → 4 bytes (SYNCGF16, SYNCGF17, SYNCGF18, and SYNCGF19 bytes)
Start pattern bit error tolerance:
00 → 0 errors
Ptol
2,1
r/w
01 → 1 error
10 → 2 errors
11 → 3 errors
-
0
-
Not used
Table 33
0x13 - RXCFG13 [default 0x0C]
Name
OOK_Thresh
Bits
R/W
7..0
r/w
Description
OOK fixed threshold or minimum threshold in peak mode. Default is 6 dB.
00000000b → 0 dB
00000001b → 0.5 dB
00001100b → 6 dB
11111111b → 127 dB
Table 34
0x14 - RXCFG14 [default 0x00]
Name
RSSI
Bits
7..0
R/W
r
Description
RSSI Output
Table 35
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 36 of 67
TRC105 - 10/16/12
0x15 - RXCFG15 [default 0x00]
Name
Bits
R/W
Description
Reduction of max RSSI level in peak mode for OOK:
000 → 0.5 dB
001 → 1.0 dB
010 → 1.5 dB
OOK_step
7,6,5
r/w
011 → 2.0 dB
100 → 3.0 dB
101 → 4.0 dB
110 → 5.0 dB
111 → 6.0 dB
OOK peak mode update period:
000 → once per chip period
001 → once per 2 chip periods
010 → once per 4 chip periods
OOK_length
4,3,2
r/w
011 → once per 8 chip periods
100 → 2x per chip period
101 → 4x per chip period
110 → 8x per chip period
111 → 16x per chip period
OOK IIR filter coefficients in AVG mode. FCAG is the cutoff frequency for the averaging filter.
00 → FCAG = chip rate / 32*π
OOK_IIR_coeff
1,0
r/w
01 → FCAG = chip rate / 8*π
10 → FCAG = chip rate / 4*π
11 → FCAG = chip rate / 2*π
Table 36
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 37 of 67
TRC105 - 10/16/12
4.4 Start Pattern Configuration Registers (SYNCFG)
0x16 - SYNCFG16 [default 0x00]
Name
Bits
R/W
Sync_Pat3
7..0
r/w
Description
Start pattern most significant byte. This byte is sent first if one or more start pattern bytes are used.
Default: 00000000b
Table 37
0x17 - SYNCFG17 [default 0x00]
Name
Bits
R/W
Sync_Pat2
7..0
r/w
Description
Start pattern byte. This byte is sent second if two or more start pattern bytes are used.
Default: 00000000b
Table 38
0x18 - SYNCFG18 [default 0x00]
Name
Bits
R/W
Sync_Pat1
7..0
r/w
Description
Start pattern byte. This byte is sent third if three or more start pattern bytes are used.
Default: 00000000b
Table 39
0x19 - SYNCFG19 [default 0x00]
Name
Bits
R/W
Sync_Pat0
7..0
r/w
Description
Start pattern least significant byte. This byte is sent last if four start pattern bytes are used.
Default: 00000000b
Table 40
4.5 Transmitter Configuration Registers (TXCFG)
0x1A - TXCFG1A [default 0x70h]
Name
Bits
R/W
Description
Transmitter anti-aliasing filter cutoff frequency:
TxInterpfilt
7,6,5,4
r/w
FCTX = 200*(FXTAL/12800)*((K + 1)/8), where FCTX is the 3 dB bandwidth of the transmitter anti-aliasing
filters in kHz, FXTAL is the crystal frequency in kHz, and K is the integer value of TxInterpfilt,.
TxInterpfilt default = 0111b, FCTX = 200 kHz
Transmitter output power (approx 3 dB steps):
000 → 13 dBm
001 → 10 dBm
010 → 7 dBm
Pout
3,2,1
r/w
011 → 4 dBm
100 → 1 dBm
101 → -2 dBm
110 → -5 dBm
111→ -8 dBm
-
0
Not used
Table 41
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 38 of 67
TRC105 - 10/16/12
4.6 Oscillator Configuration Register (OSCFG)
0x1B - OSCFG1B [default 0xBC]
Name
Bits
R/W
7
r/w
Description
Buffered Clock Output Enable:
Clkout_En
0 → Disabled
1 → Enabled
Buffered clock output frequency on pin CLKOUT:
Clk_Freq
6..2
r/w
FBCO = FXTAL/ (2* M), where FBCO is the buffered clock output frequency in kHz, FXTAL is the crystal
frequency in kHz and M is the value of Clk_Freq except if Clk_Freq is 0, FBCO = FXTAL
Clk_Freq default: 01111, FBCO = 426.67 kHz for a 12,800 kHz crystal
-
1,0
Not used
Table 42
4.7 Packet Handler Configuration Registers (PKTCFG)
0x1C - PKTCFG1C [default 0x00]
Name
Bits
R/W
7
r/w
Description
Manchester encoding/decoding enable:
Man_En
0 → Manchester encoding/decoding OFF
1 → Manchester encoding/decoding ON
Packet length: the payload size in fixed length mode, the maximum length byte value in variable
Pkt_len
6..0
r/w
length mode, and the maximum length byte value in extended variable length packet mode.
Pkt_len default: 0000000b
Table 43
0x1D - PKTCFG1D [default 0x00]
Name
Bits
R/W
Description
Node_Addrs
7..0
r/w
Node address used in filtering received packets in a network.
Table 44
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 39 of 67
TRC105 - 10/16/12
0x1E - PKTCFG1E [default 0x40]
Name
Bits
R/W
7
r/w
Description
Packet mode:
Pkt_mode
0 → Fixed length packet mode
1 → Variable length packet mode
Preamble Length:
00 → 1 byte
Preamb_len
6,5
r/w
01 → 2 bytes
10 → 3 bytes
11 → 4 bytes
DC-balanced scrambling enable:
Scrmb_En
4
r/w
0 → Scrambling OFF
1 → Scrambling ON
Cyclic Redundancy Check processing enable:
CRC_En
3
r/w
0 → CRC OFF
1 → CRC ON
Node address comparison for received packets:
00 → No comparison
ADDRS_cmp
2,1
r/w
01 → Compare with Node_Addrs only
10 → Compare with Node_Addrs and constant 0x00
11 → Compare with Node_Addrs and constants 0x00 or 0xFF
Calculate CRC and check result:
CRC_stat
0
r
0 → CRC failed
1 → CRC successful
This bit must be cleared by writing a 1 to its location.
Table 45
4.8 Page Configuration Register (PGCFG)
0x1F - PGCFG1F [default 0x00]
Name
Bits
R/W
7
r/w
Description
Automatically clear FIFO if CRC fails (receive only):
CRCclr_auto
0 → Clear FIFO if CRC fails
1 → Do not clear FIFO
Selects read or write FIFO while in standby mode:
RnW_FIFO
6
r/w
0 → Write FIFO
1 → Read FIFO
-
5,4,3,2
Not used
Register page select (leave set to Page 0 unless configuring low battery detect):
00 → Page 0
PAGE
1,0
r/w
01 → Page 1
10 → Not used
11 → Not used
Table 46
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 40 of 67
TRC105 - 10/16/12
4.9 Low Battery Configuration Registers (LBCFG)
Page 0x01, 0x05 - LBCFG05 [default 0xB1]
Name
Bits
R/W
7,6,5,4
r/w
3
r/w
Description
Do not change default bit pattern:
Reserved
1011 → default bit pattern
Low battery detection enable:
LB_En
0 → Detection off
1 → Detection on
Low battery detection threshold:
000 → 1.79 V
001 → 1.84 V
010 → 1.90 V
LB_Thres
2,1,0
r/w
011 → 1.97 V
100 → 2.02 V
101 → 2.08 V
110 → 2.14 V
111 → 2.20 V
Table 47
Page 0x01, 0x06 - LBCFG06 [default 0x96]
Name
Bits
R/W
7
r
Description
Low battery status:
LB_Status
0 → battery voltage below threshold
1 → battery voltage above threshold
Map low battery detect to pin 24:
LB_Out
6
r/w
0 → not mapped
1 → mapped
Reserved
5,4,3,
2,1,0
Do not change default bit pattern:
r/w
010110 → default bit pattern
Table 48
Note: take care to immediately return to configuration register memory map page 0 following a read or write to
the low battery configuration registers in page 1. Page configuration register PGCFG1F is mapped into all pages
at the same address of 0x1F. Bits 0..1 of this register control page selection. See Table 46.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 41 of 67
TRC105 - 10/16/12
5.0 Electrical Characteristics
Absolute Maximum Ratings
SYMBOL
PARAMETER
MIN
MAX
VDD
Supply Voltage
NOTES
-0.3
3.7
UNITS
V
TSTG
Storage Temperature
-55
+125
°C
ESD
JEDEC 22-A114 Class Rating
RFIN
Input Level
0
dBm
MAX
UNITS
1,2
V
Table 49
Recommended Operating Range
SYMBOL
PARAMETER
NOTES
MIN
VDD
Positive Supply Voltage
2.1
3.6
V
Top
Operating Temperature
-40
+85
°C
RFIN
Input Level
-
0
dBm
NOTES:
1. Pins 3,4,5,27,28,29,31 comply with Class 1A.
2. All other pins comply with Class 2.
Table 50
5.1 DC Electrical Characteristics
Minimum/maximum values are valid over the recommended operating range VDD = 2.1-3.6V. Typical conditions: To = 25°C; VDD = 3.3 V.
The electrical specifications given below are valid for a crystal having the specifications given in Table 3.
PARAMETER
SYM
Sleep Mode Current
Standby Mode Current,
Crystal Oscillator Running
ISB
Synthesizer Mode Current,
Oscillator and
IFM
Synthesizer Running
Receiver Mode Current,
All Receiver Blocks Running
Transmitter Mode Current
Reset Threshold
NOTES
MIN
TYP
MAX
UNITS
0.1
1
µA
12.8 MHz Crystal
65
85
µA
300-434 MHz
1.3
1.7
440-470 MHz
1.4
470-510 MHz
1.7
300-434 MHz
2.7
440-470 MHz
2.7
470-510 MHz
2.7
Pout = +10 dBm
25
30
Pout = +1 dBm
16
21
IS
IRX
ITX
VPOR
Digital Input Low Level
Vil
Digital Input High Level
Test Notes
mA
3.0
mA
1.37
RX_Low_Pwr
bit = 1
mA
V
0.2*VDD
V
Vih
0.8*VDD
Digital Input Current Low
Iil
-1
1
µA
Vil = 0 V
Digital Input Current High
Iih
-1
1
µA
Vih = VDD,
VDD = 3.3 V
Digital Output Low Level
Vol
0.1*VDD
V
Iol = -1 mA
Digital Output High Level
Voh
V
Ioh = +1 mA
0.9*VDD
V
Table 51
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 42 of 67
TRC105 - 10/16/12
5.2 AC Electrical Characteristics
Minimum/maximum values are valid over the recommended operating range VDD = 2.1-3.6V. Typical conditions: To = 25°C; VDD = 3.3 V.
The electrical specifications given below are valid for a crystal having the specifications given in Table 3.
RECEIVER
PARAMETER
SYM
MIN
RF Input Impedance
TYP
MAX
UNITS
Test Notes
ohms
differential input
0
dBm
above 0 dBm receiver input may be damaged
150
RF Input Power
dB
IC noise figure
FSK Receiver Bandwidth
50
250
kHz
Butterworth filter mode
OOK Receiver Bandwidth
50
400
kHz
polyphase filter mode
-110
dBm
Receiver Noise Figure
8
300-330 MHz
-110
FSK Sensitivity, 2 kb/s*
-3
10 BER, BW = 100 kHz
-112
FDEV = ±50 kHz
-110
300-330 MHz
-102
FSK Sensitivity, 25 kb/s*
-3
10 BER, BW = 100 kHz
-104
FDEV = ±50 kHz
dBm
-102
-110
-3
10 BER, BW = 50 kHz
434 MHz
470-510 MHz
-102
300-330 MHz
-108
OOK Sensitivity, 2 kb/s*
434 MHz
470-510 MHz
dBm
-108
434 MHz
FSK Bit Rate
1.56
200
kb/s
470-510 MHz
signal strength of unmodulated blocking signal
relative to desired signal, 1 MHz offset
signal strength of modulated co-channel signal
relative to desired signal
signal strength of adjacent signal relative to
desired signal, 600 kHz offset, modulation
same as desired signal
NRZ
OOK Bit Rate
1.56
32
kb/s
NRZ
-108
Blocking Immunity*
53
dBc
Co-channel Rejection*
-12
dBc
42
dBc
Adjacent Channel Rejection*
38
RSSI Resolution
0.5
dB
RSSI Accuracy
±3
dB
63
RSSI Dynamic Range
dB
70
Local Oscillator (LO) Emission
at maximum IF gain
at minimum IF gain
dBm
-65
*Receiver in-circuit performance with RFM recommended SAW filter and crystal.
Table 52
TRANSMITTER
PARAMETER
SYM
MIN
TYP
MAX
UNITS
Test Notes
RF Output Impedance
150
ohms
differential output
Maximum RF Output Power*
+13
dBm
including SAW filter insertion loss
RF Output Power Range*
21
dB
programmable
-46
dBc
=> 150 kHz from carrier, no modulation,
-40
dBm
no modulation
-40
dBm
no modulation
-112
-105
dBc/Hz
at 600 kHz offset
±50
±200
kHz
programmable
Spurious*
nd
rd
2 & 3 Harmonic*
th
4 and Higher Harmonics*
Phase Noise
FSK Deviation
±33
*Transmitter in-circuit performance with RFM recommended SAW filter and crystal.
Table 53
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 43 of 67
TRC105 - 10/16/12
TIMING
PARAMETER
TYP
MAX
UNITS
Test Condition
TX to RX Switch Time
SYM
MIN
500
1000
µs
osc & freq synthesizer running
RX to TX Switch Time
400
1000
µs
osc & freq synthesizer running
5
ms
SPI command to RX bit
Sleep to RX
5
ms
SPI command to TX bit
Sleep to Standby
1.5
5
ms
oscillator started
Standby to Synthesizer
500
800
µs
oscillator running
Synthesizer to RX
500
µs
osc & freq synthesizer running
Synthesizer to TX
500
µs
osc & freq synthesizer running
Freq Hop Time
180
Sleep to TX
500
µs
200 kHz hop
3
µs
programmable
-
µs
setup and hold time for TX data
TX Rise/Fall Time
TSUDATA (continuous mode)
2
-
Table 54
PLL CHARACTERISTICS
PARAMETER
SYM
Crystal Oscillator Frequency
MIN
TYP
MAX
UNITS
10
12.8
15
MHz
PLL Lock Time, 10 kHz Settle
Frequency Synthesizer Step
Test Condition
180
µs
200 kHz step
200
µs
1 MHz step
250
µs
5 MHz step
280
µs
10 MHz step
320
µs
20 MHz step
kHz
varies depending on frequency
12.5
15
16.5
pF
Crystal Oscillator Start-up Time
1.5
5
ms
from sleep mode
Synthesizer Wake-up Time
0.5
0.8
ms
crystal running, settling time to 10 kHz
300
-
330
330
-
365
365
-
400
400
-
440
MHz
different external components
required for each band
440
-
470
470
-
510
Crystal Load Capacitance
13.5
Frequency Range
Table 55
SPI TIMING
PARAMETER
MIN
TYP
MAX
UNITS
SCK for SPI_CONFIG
SYM
-
-
6
MHz
DESCRIPTION
SCK for SPI_DATA
-
-
1
MHz
SPI_CONFIG setup time
Max clock freq
Max clock freq
SPI_CONFIG TSU_SDI
250
-
-
ns
SPI_DATA TSU_SDI
312
-
-
ns
TSSCFG_L
500
-
-
ns
TSSDAT_L
625
-
-
ns
TSSCFG_H
500
-
-
ns
SPI_DATA setup time
nSS_CONFIG low to SCK rising edge.
SCK falling edge to nSS_CONFIG high.
nSS_DATA low to SCK rising edge.
SCK falling edge to nSS_DATA high.
nSS_CONFIG rising to falling edge
TSSDAT_H
625
-
-
ns
nSS_DATA rising to falling edge
Table 56
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 44 of 67
TRC105 - 10/16/12
6.0 TRC105 Design-In Steps
Designing a TRC105 into an application consists of seven steps:
1. Select the frequency band for operation from the left column in Table 57 below. This allows the frequency
specific hardware components for the TRC105 to be determined. These include the SAW filter and its
matching components and the VCO tank inductors.
2. Select the modulation type, FSK or OOK, and the RF data bit rate. This allows the configuration of the
TRC105 on-chip filters, the data and clock recovery circuitry and related parameters to be determined.
3. Select the radio regulation under which to operate. This allows the transmitter power level to be determined.
4. Select the frequency channel or channels to be used. This allows the configuration values for the frequency synthesizer to be tabulated.
5. Select the operating mode to be used: continuous, buffered or packet. For continuous mode, determine if
the TRC105 internal data and clock recovery feature will be used. This allows the configuration of a number of mode-related registers in the TRC105 to be determined. For packet or buffered mode, select the
data encoding, preamble length, start pattern, FIFO length and the mapping of the TRC105 host processor interrupts. For packet mode, select packet filtering options (address, CRC, etc.). From these decisions, values for the related configuration registers in the TRC105 can be determined.
6. If needed, prepare a battery power management strategy and determine when various system radios may
be configured for low power consumption.
7. Based on the selections and determinations above, compile the configuration data to be stored in the host
microcontroller to support TRC105 operation.
The details of each of these steps are discussed below.
6.1 Determining Frequency Specific Hardware Component Values
6.1.1 SAW Filters and Related Component Values
RFM offers a low-loss SAW RF filter for each of the TRC105’s operating bands listed in Table 57. The part numbers for these SAW filters and the values of the related tuning components are referenced to Figure 2. The SAW
filters are designed to take advantage of the TRC105’s differential output to achieve low insertion loss and high
out-of-band rejection.
1
SAW Filter
VCO Band
L1
303.325-307.300 MHz
RF3602D
300-330 MHz
bead
310.000-319.500 MHz
RF3603D
300-330 MHz
bead
Operating Band
L2 & L3
C4
L7
L8
C16
C17
2
68 nH
DNP
220 nH
short
DNP
DNP
2
68 nH
DNP
220 nH
short
DNP
DNP
2
56 nH
DNP
220 nH
3.3 nH
DNP
15 pF
2
47 nH
DNP
220 nH
33 nH
DNP
DNP
2
47 nH
DNP
220 nH
68 nH
DNP
DNP
2
39 nH
DNP
10 nH
5.6 nH
15 pF
1.2 pF
2
33 nH
DNP
220 nH
5.6 nH
DNP
1.2 pF
2
18 nH
DNP
220 nH
56 nH
DNP
DNP
342.000-348.000 MHz
RF3604D
330-365 MHz
bead
365.000-380.000 MHz
RF3605D
365-400 MHz
bead
382.000-398.000 MHz
RF3606D
365-400 MHz
bead
402.000-407.300 MHz
RF3607D
400-440 MHz
bead
418.000-434.790 MHz
RF3608D
400-440 MHz
bead
447.000-451.000 MHz
RF3609D
440-470 MHz
bead
1. XTL1020P crystal recommended as frequency reference for all operating bands.
2. Bead is Fair-Rite 2506033017Y0 or equivalent.
Table 57
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 45 of 67
TRC105 - 10/16/12
6.1.2 Voltage Controlled Oscillator Component Values
The TRC105 VCO requires four external components for operation, two tank circuit inductors and two power supply decoupling capacitors. It is important to use high-Q chip inductors in the tank circuit. This assures low phase
noise VCO operation and minimum interference from signals near the TRC105’s operating frequency due
to phase noise reciprocal mixing. The two tank circuit inductors have the same value which depends on the VCO
operating band and the PCB layout. Typical values are given in Table 58 (location of L5 & L6 shown in Figure 2):
Band
L5 & L6
Tolerance
300-330 MHz
39 nH
±5%
330-365 MHz
27 nH
±5%
365-400 MHz
27 nH
±5%
400-440 MHz
22 nH
±5%
440-470 MHz
15 nH
±5%
470-510 MHz
TBD
±5%
Table 58
The tank circuit inductors should be mounted close to their IC pads with the long axis of the coil at right angles to
the edge of the IC where the pads are located. The decoupling capacitors should be positioned on each side of
the tank circuit inductors. Other RF chokes and coils should be spaced somewhat away from the tank inductors
and positioned at right angles to minimize coupling.
VCO frequency centering is checked by looking at the voltage between pads 6 and 7. The voltage should be 150
±50 mV when the TRC105 is in transmit mode at a frequency near the center of the operating band and subband.
VCO frequency centering can be adjusted by changing the value of the tuning inductors and/or adjusting the VCO
trim bits 1 and 2 in configuration register MCFG05. The trim bits adjust the tuning voltage in increments of about
60 mV. Increasing the value of the tuning inductors increases the tuning voltage between pads 6 and 7.
6.2 Determining Configuration Values for FSK Modulation
6.2.1 Bit Rate Related FSK Configuration Values
The TRC105 supports RF bit rates (data rates) from 1.5625 to 200 kb/s for FSK modulation. There are several
considerations in choosing a bit rate. The sensitivity of the TRC105 decreases with increasing data rate. A bit rate
should be chosen that is adequate but not higher than the application requires. The exception to this rule is when
the TRC105 is operated as a frequency hopping spread spectrum transceiver in a noisy or crowded band. Running at a higher bit rate will allow a higher channel hopping rate, which provides more robust operation in a
crowded band in tradeoff for less range under quiet band conditions.
The TRC105 RF bit rate is set by the value of the bytes loaded in MCFG03 and MCFG04. For the standard crystal frequency of 12.8 MHz:
BR = 12800/(2*(C+1)*(D + 1)), with C in the range of 0 to 255, and D = 31 (default value)
Where BR is the bit rate in kb/s, FXTAL the crystal frequency in kHz, C the value in MCFG03, and D is the value in
MCFG04. This bit rate value supports both the data and clock recovery circuit in the receiver and the bit rate
clocking in the transmitter modulator. Using the default value of D and solving the equation above for C:
C = (12800 - 64*BR)/64*BR
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 46 of 67
TRC105 - 10/16/12
C must be an integer value, so BR is limited to 256 discrete values. If the value of C given in the above equation
is not an integer for your desired bit rate, round the value of C down to the nearest integer. You can then calculate
the nearest available bit rate equal to or greater than your desired bit rate.
Selection of the RF data rate allows a suitable FSK deviation to be determined. This, in turn, allows the configuration value for the anti-aliasing filters in the transmitter and the configuration values for the R-C and Butterworth
low-pass filters in the receiver to be determined.
The minimum required deviation for good TRC105 FSK performance is:
FDEV = BR
Where FDEV is the deviation in kHz and BR is the bit rate in kb/s. Specific to the TRC105, the minimum recommended deviation is ±33 kHz, even at low data rates. FDEV is configured with an integer R stored in MCFG02. For
the standard crystal frequency of 12.8 MHz:
FDEV = 12800/(32*(R + 1)), with the useable range of R 1 to 11
Where FDEV is the deviation in kHz. Solving the equation above for R:
R = (12800 - 32*FDEV)/32*FDEV
R must be an integer value, so FDEV is limited to 11 discrete values. If the value of R given in the above equation
is not an integer for your desired deviation, round the value of R down to the nearest integer and use this value to
meet or exceed the minimum required deviation for the bit rate you are using.
Once BR and FDEV have been determined, the bandwidths and related configuration values for the TRC105 filters
can be determined. The recommended 3 dB bandwidth (cutoff frequency) for the transmitter anti-aliasing filters is:
FCTX = 3*FDEV + 1.5*BR
Where FCTX is the 3 dB bandwidth of the transmitter anti-aliasing filters in kHz, FDEV is the frequency deviation in
kHz and BR is the bit rate in kb/s. FCTX is configured with bits 7..4 in TXCFG1A. For the standard crystal frequency of 12.8 MHz:
FCTX = 200*(K + 1)/8, with K in the range of 0 to 15
Where FCTX is the 3 dB bandwidth of the transmitter anti-aliasing filters in kHz and K is the integer value of the bit
pattern in TXCFG1A bits 7..4. Solving the equation above for K:
K = (FCTX - 25)/25
K must be an integer value, so FCTX is limited to 16 discrete values. If the value of K given in the above equation is
not an integer for your desired deviation, round the value of K down to the nearest integer and use this value to
set the bandwidth of the transmitter anti-aliasing filters. For operation at 90 kb/s and above, use a value of 15
for K.
The recommended 3 dB bandwidth for the receiver Butterworth filters is:
FCBW = 2*FDEV + BR
Where FCBW is the 3 dB bandwidth of the Butterworth filters in kHz, FDEV is the frequency deviation in kHz and BR
is the bit rate in kb/s. This equation assumes use of the high accuracy, low drift XTL1020P crystal. If an alternative crystal is used, add ½ the expected drift due to temperature and aging to the equation above. FCBW is configured with bits 3..0 in RXCFG10. For the standard crystal frequency of 12.8 MHz:
FCBW = 200*(J + 1)/8, with J in the range of 0 to 15
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 47 of 67
TRC105 - 10/16/12
Where FCBW is the 3 dB bandwidth of the receiver Butterworth filters in kHz and J is the integer value of the bit
pattern in RXCFG10 bits 3..0. Using a standard 12.8 MHz crystal, the equation for determining J is:
J = (FCBW - 25)/25
J must be an integer value, so FCBW is limited to 16 discrete values. If the value of J given in the above equation is
not an integer for your deviation and bit rate, round the value of J down to the nearest integer and use this value
to set the bandwidth of the receiver Butterworth filters for the bit rate you are using. For operation at 133 kb/s and
above, use a value of 15 for J.
The recommended 3 dB bandwidth for the receiver R-C filters is:
FCRC = 3.25*FCBW
Where FCRC and FCBW are in kHz. The bandwidth of FCRC is set by bits 7..4 in RXCFG10. The relationship of the RC filter bandwidth to the integer value in RXCFG10 bits 7..4 is given in Table 59. Where the calculated value for
FCRC falls between table values, use the higher table value. For operation at 100 kb/s and above, use the 987 kHz
R-C filter bandwidth.
Pattern of Bits 7..4
R-C Filter Bandwidth
0000
65 kHz
0001
82 kHz
0010
109 kHz
0011
137 kHz
0100
157 kHz
0101
184 kHz
0110
211 kHz
0111
234 kHz
1000
262 kHz
1001
321 kHz
1010
378 kHz
1011
414 kHz
1100
458 kHz
1101
514 kHz
1110
676 kHz
1111
987 kHz
Table 59
6.2.2 Determining Transmitter Power Configuration Values
European ETSI EN 300 220-1 regulates unlicensed radio operation in the 433.05 to 434.97 MHz band. A
transmitter power level up to 10 dBm can be used in this band, subject to certain restrictions. See EN 300 220-1
for details.
FCC Part 15 and Canadian RSS-210 regulate unlicensed radio operation in several bands covered by the
TRC105. The allowed transmitter power level (field strength) depends on the operating frequency and application.
See these documents for details.
The use of the TRC105 is supported by various radio regulations in almost every geographic location in the world.
Please contact RFM’s local Field Application Engineer for additional information.
The relationship of the transmitter power level to the integer value of TXCFG1A bits 3..1 is given in Table 60.
There are eight available power settings (approximate):
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 48 of 67
TRC105 - 10/16/12
Pattern of Bits 3..1
Transmitter Power
000
13 dBm
001
10 dBm
010
7 dBm
011
4 dBm
100
1 dBm
101
-2 dBm
110
-5 dBm
111
-8 dBm
Table 60
The highest power setting allowed under the governing radio regulations is usually chosen unless the application
operates at short range and minimum DC power consumption is critical.
6.3 Determining Configuration Values for OOK Modulation
6.3.1 Bit Rate Related OOK Configuration Values
The TRC105 supports RF bit rates (data rates) from 1.5625 to 33.33 kb/s for OOK modulation. As with FSK modulation, there are several considerations in choosing an OOK data rate. The sensitivity of the TRC105 decreases
with increasing bit rate. A bit rate should be chosen that is adequate but not higher than the application requires.
The exception to this rule is when the TRC105 is operated as a frequency hopping spread spectrum transceiver in
a noisy or crowded band. Running at a higher bit rate will allow a higher channel hopping rate, which provides
more robust operation in a crowded band in tradeoff for less range under quiet band conditions.
The TRC105 RF bit rate is set by the value of the bytes loaded in MCFG03 and MCFG04. For the standard crystal frequency of 12.8 MHz:
BR = 12800/(2*(C+1)*(D + 1)), with C in the range of 0 to 255, and D = 31 (default value)
Where BR is the bit rate in kb/s, FXTAL the crystal frequency in kHz, C the value in MCFG03, and D is the value in
MCFG04. This bit rate value supports both the data and clock recovery circuit in the receiver and the bit rate
clocking in the transmitter modulator. Using the default value of D and solving the equation above for C:
C = (12800 - 64*BR)/64*BR
C must be an integer value, so BR is limited to 256 discrete values. If the value of C given in the above equation
is not an integer for your desired bit rate, round the value of C down to the nearest integer. You can then calculate
the nearest available bit rate equal to or greater than your desired bit rate.
In OOK mode, the second IF frequency FIF2 is normally set to 100 kHz. The discussion in the rest of this section
assumes FIF2 is 100 kHz.
Once BR and FIF2 has been determined, the bandwidths and related configuration values for the TRC105 filters
can be determined. The recommended 3 dB bandwidth for the transmitter anti-aliasing filters is:
FCTX = 3*FIF2 = 300 kHz
FCTX is configured with bits 7..4 in TXCFG1A. For the standard crystal frequency of 12.8 MHz:
FCTX = 200*(K + 1)/8, with K in the range of 0 to 15
Where FCTX is the 3 dB bandwidth of the transmitter anti-aliasing filters in kHz and K is the integer value of the bit
pattern in TXCFG1A bits 7..4. The equation for determining K is:
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 49 of 67
TRC105 - 10/16/12
K = (FCTX - 25)/25 = 11 for FCTX = 300 kHz
For OOK operation, the receiver filters are configured as polyphase band-pass filters by setting RXCFG12 bit 7 to
1. The center frequency of the polyphase filters is set to 100 kHz to match the second IF frequency. The center
frequency, FOPP, is configured with bits 7..4 in RXCFG11. For the standard crystal frequency of 12.8 MHz:
FOPP = 200*(L + 1)/8, with L in the range of 0 to 15
Where FOPP is the center frequency of the OOK polyphase filter in kHz, L is the integer value of the bit pattern in
RXCFG11 bits 7..4. The equation for determining L is:
L = (FOPP - 25)/25 = 3 for FOPP = 100 kHz
The recommended upper cutoff frequency for the receiver polyphase band-pass filters is:
FCPP = FOPP + BR
Where FCPP is the upper cutoff frequency of the polyphase filters in kHz and BR is the bit rate in kb/s. This equation assumes use of the high accuracy, low drift XTL1020P crystal. If an alternative crystal is used, add ½ the expected drift due to temperature and aging to the equation above. FCPP is configured with bits 3..0 in RXCFG10.
For the standard crystal frequency of 12.8 MHz:
FCPP = 100 + 200*(J + 1)/8, with the usable range of J 0 to 1
Where FCPP is the upper cutoff frequency of the receiver OOK polyphase filter in kHz and J is the integer value of
the bit pattern in RXCFG10 bits 3..0. The equation for determining J is:
J = (FCPP - 125)/25
J must be an integer value, so FCPP is limited to 2 discrete values: 125 kHz and 150 kHz. Choose the value of J
that provides the FCCP value that is nearest to the value calculated for the bit rate you are using. The recommended 3 dB bandwidth for the receiver R-C filters is:
FCRC = 3.25*FCPP
Where FCRC and FCPP are in kHz. The bandwidth of FCRC is set by bits 7..4 in RXCFG10. The relationship of the
R-C filter bandwidth to the integer value in RXCFG10 bits 7..4 is given in Table 61. The matching values for the
125 and 150 kHz FCCP values are shown in bold:
Pattern of Bits 7..4
R-C Filter Bandwidth
0000
65 kHz
0001
82 kHz
0010
109 kHz
0011
137 kHz
0100
157 kHz
0101
184 kHz
0110
211 kHz
0111
234 kHz
1000
262 kHz
1001
321 kHz
1010
378 kHz
1011
414 kHz
1100
458 kHz
1101
514 kHz
1110
676 kHz
1111
987 kHz
Table 61
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 50 of 67
TRC105 - 10/16/12
6.3.2 OOK Demodulator Related Configuration Values
OOK demodulation in the TRC105 is accomplished by comparing the RSSI to a threshold value. An RSSI value
greater than the threshold is “sliced” to a logic 1, and an RSSI value equal or less than the RSSI value is sliced to
a logic 0. The TRC105 provides three threshold options - fixed threshold, average-referenced threshold, and
peak-referenced threshold. MCFG01 bits 3..2 select the OOK threshold as shown in Table 62:
Pattern of Bits 3..2
Threshold
00
fixed
01
peak referenced
10
average referenced
11
not used
Table 62
The configuration settings for each of these threshold options depend directly or indirectly on the bit rate.
The fixed-threshold value is configured in MCFG13. The fixed threshold can be adjusted in 0.5 dB increments
over a range of 128 dB. Also, the gain of the IF can be adjusted over a range of 13.5 dB to reduce the RSSI value
under no signal conditions. MCFG01 bits 1..0 select the IF gain as shown in Table 63:
Pattern of Bits 1..0
IF Gain
00
maximum
01
-4.5 dB
10
-9.0 dB
11
-13.5 dB
Table 63
The useable threshold setting depends on the RF operating band, the bandwidths of the receiver filters, the RF
noise generated by host circuitry, the RF noise generated in the application environment, and the antenna efficiency. The fixed threshold is adjusted heuristically by incrementing the threshold while monitoring the data output
pin with an oscilloscope. The threshold is adjusted upward under no signal conditions until noise spikes on the
data output are reduced to an average of one spike every five or more seconds. Because the fixed threshold has
no automatic adjustment capability, it should only be used in applications where incidental RF noise generators
such as PCs, switchgear, etc., are not present.
The average-referenced threshold is generated by passing the RSSI signal through a low-pass filter. Four cutoff
frequencies can be configured for this filter with RXCFG15 bits 1..0, as shown in Table 64 below:
Pattern of Bits 1..0
Cutoff Frequency
00
chip rate/32*π
01
chip rate/8*π
10
chip rate/4*π
11
chip rate/2*π
Table 64
The chip rate is equal to the bit rate except when Manchester encoding is used. For Manchester encoding, the
chip rate is equal to twice the bit rate. An adequately long 1-0-1-0… preamble must be transmitted to center the
average-referenced threshold. A preamble of at least 24 bits is recommended. The average-referenced threshold
should be used in conjunction with a mechanism to avoid transmitting a long sequence of bits of the same value,
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 51 of 67
TRC105 - 10/16/12
such as the TRC105’s data scrambling or Manchester encoding options. The average-referenced threshold running with a chip rate/2*π cutoff frequency is a good choice for the majority of OOK applications.
The peak-referenced threshold is generated from the RSSI signal using a fast attack, slow decay peak detector
emulation. The slicer threshold is immediately set to 6 dB below the peak value of the RSSI signal anytime the
RSSI value exceeds the threshold by 6 dB. The threshold then decays by a configurable dB step when a configurable interval passes without the RSSI signal peaking 6 dB above the threshold. The decay step is configured with
RXCFG15 bits 7..5 as shown in Table 65:
Pattern of Bits 7..5
Decay Step
000
0.5 dB
001
1.0 dB
010
1.5 dB
011
2.0 dB
100
3.0 dB
101
4.0 dB
110
5.0 dB
111
6.0 dB
Table 65
The decay interval is configured with RXCFG15 bits 4..2 as shown in Table 66:
Pattern of Bits 4..2
Decay Interval
000
once per chip
001
once per 2 chips
010
once per 4 chips
011
once per 8 chips
100
twice per chip
101
four times per chip
110
8 times per chip
111
16 times per chip
Table 66
The chip period tCP is equal to the bit period except when Manchester encoding is used. For Manchester encoding, the chip period is equal to ½ the bit period:
tCP = 1/BR without Manchester encoding, tCP = 1/(2*BR) with Manchester encoding
Where tCP is in ms and BR is in kb/s. The default values of 0.5 dB per decay step and 1 decay interval per chip
provide a good starting point for most applications. For application environments that contain pulse noise, such as
operation in a band where other FHSS systems are operating, using Manchester encoding and decreasing the
decay interval to twice or four times per chip and/or increasing the decay step to 1 dB will reduce the “blinding”
effect of pulse noise. Multipath flutter tolerance is also improved by using Manchester encoding and decreasing
the decay interval and/or increasing the decay step size.
6.3.3 OOK Transmitter Related Configuration Values
MCFG05 bits 7..6 allow the rise and fall time of the power amplifier regulator to be adjusted. Using the default
component values for R6 and C5 as shown in Figure 2, the rise and fall times for the power amplifier regulator
and the OOK modulation are given in Table 67:
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 52 of 67
TRC105 - 10/16/12
Pattern of Bits 4..3
Regulator Rise/Fall Times
OOK Rise/Fall Time
00
3/3 µs
2.5/2 µs
01
8.5/8.5 µs
5/3 µs
10
15/15 µs
10/6 µs
11
23/23 µs
20/10 µs
Table 67
It is generally a good practice to set the OOK rise and fall time to about 5% of a bit period to avoid excessive
modulation bandwidth:
tOOK = 50/BR
Where tOOK is the nominal 5% OOK rise/fall time in µs and BR is the bit rate in kb/s. At low OOK data rates the
20/10 µs rise/fall times given in the table above are satisfactory. When operating in the 434 MHz band under ETSI
EN300 220-1 regulations, check the modulation bandwidth carefully at bit rates above 8 kb/s to confirm compliance. For operation in certain parts of the 434 MHz band, the required rise and fall time may be greater than 5%.
6.4 Frequency Synthesizer Channel Programming for FSK Modulation
When using a standard 12.8 MHz reference crystal, the FSK RF channel frequency is:
FRF = 14.4*(75*(P + 1) + S)/(R + 1), with P and S in the range 0 to 255, R in the range 64 to 169
Where FRF is in MHz, and P, S, and R are divider integers with S less than (P + 1). There are two sets of three
registers that hold the values of P, S and R:
Register
Divider Parameter
MCFG06
R1
MCFG07
P1
MCFG08
S1
MCFG09
R2
MCFG0A
P2
MCFG0B
S2
Table 68
MCFG05 bit 0 selects the register set to use with the frequency synthesizer. A 0 value selects register set
MCFG06-MCFG08 and a 1 value selects register set MCFG09-MCFG0B. In addition, MCFG00 bits 4..2 select the
VCO operating band as follows:
MCFG00 bits 4..2
Band, MHz
000
300-330
001
330-365
010
365-400
011
400-440
100
440-470
101
470-510
Table 69
The dual register set allows a new frequency to be completely entered in one register set while operating on the
other register set. It is important to load all three divider parameters into a register set before switching control to
it. Otherwise, a transient out-of-band frequency shift can occur. The dual register set facilitates FHSS operation,
as the operating frequency for the next hop can be loaded anytime during the current hop interval, making this
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 53 of 67
TRC105 - 10/16/12
programming task less time critical. The values of P, S and R for FSK operation on several common frequencies
are given in Table 70. Software for determining P, S and R values for any in-band frequency is provided with the
TRC105 development kit.
Configuration
315 MHz
434 MHz
447 MHz
MCFG00 bits 4..2
000
011
100
P
34
42
58
S
0
30
45
R
119
107
143
Table 70
6.5 Frequency Synthesizer Channel Programming for OOK Modulation
When using a standard 12.8 MHz reference crystal the RF channel frequency for OOK receive is:
FTXRF = (14.4*(75*(P + 1) + S)/(R + 1)) - FDEV, with P, S in the range 0 to 255, R in the range of 64 to 169
Where FTXRF and transmitter deviation frequency FDEV are in MHz, and P, S, and R are divider integers where S
must be less than (P+1). An FDEV value of 0.1 MHz is normally used, which must match the receiver low IF frequency FIF2. There are two sets of three registers that hold the values of P, S and R:
Register
Divider Parameter
MCFG06
R1
MCFG07
P1
MCFG08
S1
MCFG09
R2
MCFG0A
P2
MCFG0B
S2
Table 71
MCFG05 bit 0 selects the register set to use with the frequency synthesizer. A 0 value selects register set
MCFG06-MCFG08 and a 1 value selects register set MCFG09-MCFG0B. In addition, MCFG00 bits 4..2 select the
VCO operating band as follows:
MCFG00 bits 4..2
Band, MHz
000
300-330
001
330-365
010
365-400
011
400-440
100
440-470
101
470-510
Table 72
The dual register set allows a new frequency to be completely entered in one register set while operating on the
other register set. It is important to load all three divider parameters into a register set before switching control to
it. Otherwise, a transient out-of-band frequency shift can occur. The dual register set facilitates FHSS operation,
as the operating frequency for the next hop can be loaded anytime during the current hop interval, making this
programming task less time critical. The values of P, S and R for OOK receive operation on several common frequencies are given in Table 73 for a 0.1 MHz FIF2. Software for determining P, S and R values for any in-band
frequency is provided with the TRC105 development kit.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 54 of 67
TRC105 - 10/16/12
Configuration
315 MHz
434 MHz
447 MHz
MCFG00 bits 4..2
000
011
100
P
41
76
58
S
1
13
46
R
143
191
143
Table 73
The RF channel frequency for OOK transmit is:
FRXRF = (14.4*(75*(P + 1) + S)/(R + 1)) - FIF2, with P, S in the range 0 to 255, R in the range of 64 to 169
Where FRXRF and the OOK 2nd IF frequency FIF2 are in MHz, and P, S, and R are divider integers where S must be
less than (P+1), and R has a value in the range of 64 to 169. An FIF2 value of 0.1 MHz is normally used. The values of P, S and R for OOK transmit operation on several common frequencies are given in Table 74 for a
0.1 MHz FIF2. Software for determining P, S and R values is provided with the TRC105 development kit.
Configuration
315 MHz
434 MHz
447 MHz
MCFG00 bits 4..2
000
011
100
P
41
76
58
S
1
13
46
R
143
191
143
Table 74
6.6 TRC105 Data Mode Selection and Configuration
The TRC105 supports three data modes: Continuous, Buffered and Packet. Continuous data mode provides the
most formatting flexibility, but places the heaviest demand on host microcontroller resources and requires the
most custom firmware development. In contrast, the Packet data mode unloads the host processor and the application firmware from handing tasks such as DC-balanced data encoding, packet frame assembly and disassembly, error detection, packet filtering and FIFO buffering. The trade-off for Packet data mode is limited flexibility in
data formatting parameters such as packet frame design. Buffered data mode falls between Packet and Continuous data mode capabilities, providing FIFO buffering, but allowing considerable flexibility in the design of the
packet frame.
Packet data mode is generally preferred as it supports the fastest application development time and requires the
smallest and least expensive host microcontroller. Buffered data mode covers applications that require a specific
packet frame design to support features such as multi-hop routing. Continuous data mode is reserved for specialized requirements, such as compatibility with a legacy product.
MCFG01 bits 7..6 select the data mode. A 00 bit pattern selects Continuous data mode. A 01 bit pattern selects
Buffered data mode. Bit patterns 10 or 11 select Packet data mode. The TRC105 configuration details for each
data mode are discussed below.
6.6.1 Continuous Data Mode
In Continuous data mode operation, transmitted data streams are applied to DATA Pin 20, and received data
streams are output on Pin 20. IRQ1 Pin 22 is usually configured to supply a clock signal to the host microcontroller to pace the transmitted and received data steams. The clock signal is generated at the configured bit
rate. When transmitting, bits are clocked into Pin 20 on the low-to-high clock transitions at Pin 22.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 55 of 67
TRC105 - 10/16/12
Received bits are valid (clocked out) on Pin 20 on low-to-high clock transitions on Pin 22. The clock signal is controlled by RXCFG12 bit 6. Setting this bit to 0 enables bit clocking and setting this bit to 1 disables bit clocking.
Clocking must be used for FSK transmissions. It is optional for OOK transmissions.
While clocking is optional for FSK and OOK reception, enabling clocking provides additional bit stream filtering
and regeneration, even if the clock signal is not used by the microcontroller. To effectively use the data and clock
recovery feature, data must be transmitted with a bit rate accuracy of better than ±2%, and a 1-0-1-0… training
preamble of at least 24 bits must be sent at the beginning of a transmission. When clocking is enabled, continuous mode will optionally support the detection of a start-of-packet (start) pattern when receiving. The start pattern
must be generated by the host microcontroller when transmitting. Start pattern detection is enabled by setting
RXCFG12 bit 5 to 1. The length of the start pattern is set by RXCFG12 bits 4..3 as follows:
RXCFG12 bits 4..3
Pattern Length
00
8 bits
01
16 bits
10
24 bits
11
32 bits
Table 75
The number of allowed bit errors in the start pattern is configured by RXCFG12 bits 2..1 as follows:
RXCFG12 bits 2..1
Error Tolerance
00
none
01
1 bit
10
2 bits
11
3 bits
Table 76
For most applications, a start pattern length of 24 to 32 bits is recommended with the error tolerance set to none.
The start pattern is stored in registers SYNCFG16 through SYNCFG19. Received bits flow through a shift register
for pattern comparison with the most significant bit of SYNCFG16 compared to the earliest received bit and the
least significant bit of the last register (selected by the pattern length) compared to the last received bit. Pattern
detection is usually output on IRQ0, as discussed below. Refer to Figure 9 for pattern detection output timing. A
well designed pattern should contain approximately the same number of 1 and 0 bits to achieve DC-balance, it
should include frequent bit transitions, and it should be a pattern that is unlikely to occur in the encoded data following it.
As shown in Figure 19, two interrupt (control) outputs, IRQ0 and IRQ1, are provided by the TRC105 to coordinate
data flow to and from the host microcontroller. In Continuous data mode, one of two signals can be mapped to
IRQ0. This mapping is configured in register IRQCFG0D. Bits 7..6 select the signal for IRQ0 in the receive mode.
The mapping options for Continuous data mode are summarized in Table 77, where X denotes a don’t care bit
value. Note that IRQ1 always outputs DCLK in Continuous data mode when clocking is enabled.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 56 of 67
TRC105 - 10/16/12
IRQCFG0D bits
Cfg
State
IRQ
Source
7..6
00, 1X
RX
0
Start Pattern Detect
7..6
01
RX
0
RSSI
3
X
TX
0
no signal (0)
5..4
XX
RX
1
DCLK
2
X
TX
1
DCLK
Table 77
The motivation for disabling clocking when transmitting or receiving OOK is that non-standard bit rates can be
used. However, the host microcontroller must handle the data and clock recovery functions. When using continuous mode with or without clocking enabled, data should be encoded to provide DC-balance (same number of 1
and 0 bits) and limited run lengths of the same bit value. Manchester encoding, 8-to-12 bit symbolizing or scrambling must be applied to the data before transmitting and removed after receiving to achieve good RF transmission performance. The preamble, start pattern and error checking bits must also be generated by the host microcontroller to establish robust data communications.
6.6.2 Buffered Data Mode
In Buffered data mode operation, the transmitted and received data bits pass through the SPI port in groups of
8 bits to the internal TRC105 FIFO. Bits flow from the FIFO to the modulator for transmission and are loaded into
the FIFO as data is received. As discussed in Sections 3.10 and 3.11, the SPI port can address the data FIFO or
the configuration registers. Asserting a logic low on the nSS_DATA input addresses the FIFO, and asserting a
logic low on the nSS_CONFIG addresses the configuration registers. If both of these inputs are asserted,
nSS_CONFIG will override nSS_DATA. The TRC105 acts as an SPI slave and receives clocking from its host
microcontroller. SPI read/write details are provided in Sections 3.10 and 3.11. As shown in Figure 19, two interrupt (control) outputs, IRQ0 and IRQ1, are provided by the TRC105 to coordinate SPI data flow to and from the
host microcontroller. One to four signals can be selected or mapped to each interrupt output. This mapping is configured in register IRQCFG0D. Bits 7..6 select the signal for IRQ0 in the receive mode, and Bit 3 selects the IRQ0
signal in transmit mode. Bits 5..4 select the signal for IRQ1 in the receive mode, and Bit 2 selects the IRQ1 signal
in transmit mode. The mapping options for Buffered data mode are summarized in Table 78:
IRQCFG0D bits
Cfg
State
IRQ
Source
7..6
00
RX
0
no signal (0)
Write_byte (high pulse when received byte written to FIFO)
7..6
01
RX
0
7..6
10
RX
0
nFIFOEMPTY
7..6
11
RX
0
Start Pattern Detect
3
1
TX
0
FIFO_Int_Tx
3
0
TX
0
nFIFOEMPTY
5..4
00
RX
1
no signal (0)
5..4
01
RX
1
FIFOFULL
5..4
10
RX
1
RSSI_IRQ
5..4
11
RX
1
FIFO_Int_Rx
2
0
TX
1
FIFOFULL
2
1
TX
1
TX_Stop
Table 78
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 57 of 67
TRC105 - 10/16/12
In addition, IRQCFG0E allows several internal interrupts to be configured. See Table 79 below:
IRQCFG0E bits
Cfg
Internal Interrupt Control
7
0
Start FIFO fill when start pattern detected
7
1
Control FIFO with bit 6
6
0
Stop filling FIFO (if bit 7 is 0, this is start pattern detect)
6
1
Start filling FIFO
5
0
Transmitting all pending bits in FIFO
5
1
All bits in FIFO transmitted
4
0
FIFO OK
4
1
FIFO overflow (write 1 to reset FIFO)
3
0
Disable RSSI interrupt (bit 2)
3
1
Enable RSSI interrupt (bit 2)
2
1
RF signal ≥ RSSI threshold
2
0
RF signal < RSSI Threshold
1
1
PLL not locked
1
0
PLL locked
0
1
PLL_LOCK signal disabled (bit 1 above), Pin 23 set high
0
0
PLL_LOCK signal enabled
Table 79
MCFG0C bits 7..6 set the length of the FIFO as shown in Table 80:
MCFG0C bits 7..6
FIFO Length
00
16 bytes
01
32 bytes
10
48 bytes
11
64 bytes
Table 80
The integer value of MCFG0C bits 5..0 plus 1 sets the FIFO interrupt threshold. When receiving in Buffered data
mode, FIFO_Int_Rx is triggered when the number of bytes in the FIFO is equal to or greater than the threshold.
The FIFO threshold facilitates sending and receiving messages longer than the chosen FIFO length, by signaling
when additional bytes should be added to the FIFO during a packet transmission and retrieved from the FIFO during a packet reception. Two additional interrupts, nFIFOEMPY and FIFOFULL provide signaling that a packet
transmission is complete or a full packet has been received respectively.
The following is a typical Buffered data mode operating scenario. There are many other ways to configure this
very flexible data mode.
1. Switch to standby mode by setting MCFG00 bits 7..5 to 001.
2. Set the FIFO to a suitable size for the application in MCFG0C bits 7..6.
3. Set the start pattern length in RXCFG12 bits 4..3.
4. Load the start pattern in registers SYNCFG16 up through SYNCFG19 as required.
5. Set IRQCFG0E bit 7 to 0. In receive, the FIFO will start filling when a start pattern is detected.
6. Set IRQCFG0D bit 7..6 to 01. In receive, IRQ0 will flag each time a byte is ready to be retrieved.
7. Set IRQCFG0D bit 5..4 to 00. IRQ1 signaling will not be required in receive mode.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 58 of 67
TRC105 - 10/16/12
8. In transmit mode, IRQ0 will flag when the FIFO is empty.
9. Set IRQCFG0D bit 3 to 1. IRQ1 will flag when the last bit starts to be transmitted.
10. Load the operating frequency into register set MCFG06-MCFG08 or MCFG09-MCFG0B.
11. Select the register set to use by setting MCFG05 bit 0. A 0 value selects register set MCFG06-MCFG08
and a 1 value selects register set MCFG09-MCFG0B.
12. When ready to transmit, place the TRC105 in synthesizer mode by setting MCFG00 bits 7..5 to 010. Monitor the TRC105 Pin 23 to confirm PLL lock.
13. Place TRC105 in transmit mode by setting MCFG00 bits 7..5 set to 100.
14. Load the message in the FIFO through the SPI port. In Buffered data mode, the transmitted message
must include the 1-0-1-0… training preamble, the start pattern and the data. A length byte at the beginning of the data or a designated end-of-message character is normally used to indicate message length.
15. Monitor IRQ1. It sets when the when the last bit starts to be transmitted. Allow one bit period for the last
bit to be transmitted and then switch to standby mode by setting MCFG00 bits 7..5 to 001.
16. To prepare for receive mode, write a 1 to IRQCFG0E bit 6. This arms the start pattern detection.
17. Switch the TRC105 from standby mode to synthesizer mode by setting MCFG00 bits 7..5 set to 010.
Monitor the TRC105 Pin 23 to confirm PLL lock.
18. Switch from synthesizer mode to receive mode by setting MCFG00 bits 7..5 to 011.
19. Following a start pattern detection, the FIFO will start filling. Note that the preamble and start pattern are
not loaded in the receive FIFO.
20. As each data byte is loaded into the FIFO, IRQ0 will pulse to alert the host microcontroller to retrieve
the byte.
21. The host microcontroller can use a countdown on the length byte or detection of the end-of-message byte
to determine when all of the message data has been retrieved.
22. As soon as all the message has been retrieved, switch the TRC105 to standby mode by setting MCFG00
bits 7..5 to 001.
23. From standby mode, enter another transmit cycle as outlined in steps 12 through 15, or enter another receive cycle as outlined in steps 16 through 23.
It is possible to transmit messages longer than the FIFO in Buffered data mode by monitoring the nFIFOEMPY
flag and immediately loading additional data bytes. However, messages sent by low power radios such as the
TR103 are normally 127 bytes or less to reduce the chances of corruption due to noise, fading or interference.
6.6.3 Packet Data Mode
The Packet data mode is built on top of the Buffered data mode, and adds a number of standard and optional features:

Fixed or variable length packet options

Generation of preamble and start pattern (network ID) in transmit mode

DC-balancing of data by scrambling (whitening) or Manchester encoding


Generation of a 16-bit error detection CRC
Optional 1-byte node address and/or 1-byte length address
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 59 of 67
TRC105 - 10/16/12

Recognition of start pattern in receive mode

Automatic removal of preamble and start pattern in receive mode (payload only in FIFO)

Flagging of received packets with errors or flagging and discard of packets with errors

Filtering of received packets based on address byte - address match only, address byte plus 0x00 broadcast address or address byte plus 0x00 and 0xFF broadcast addresses

New IRQ0 and IRQ1 mapping options
The SPI interface is used with Packet data mode as with Buffered data mode. IRQ0 and IRQ1 mapping is configured in register IRQCFG0D. Bits 7..6 select the signal for IRQ0 in the receive mode. In transmit mode, IRQ0
mapping is set by IRQCFG0D bit 3. IRQCFG0D bits 5..4 select the signal for IRQ1 in the receive mode. Bit 3 selects the IRQ1 signal in transmit mode. The mapping options for Packet data mode are summarized in Table 81
below:
IRQCFG0D bits
Cfg
State
IRQ
Source
7..6
00
RX
0
Data_Rdy (CRC OK)
Write_byte (high pulse when received byte written to FIFO)
7..6
01
RX
0
7..6
10
RX
0
nFIFOEMPY (low when FIFO is empty)
7..6
11
RX
0
Start Pattern Detect or Node Address Match
3
1
TX
0
FIFO_Int_Tx
3
0
TX
0
nFIFOEMPY
5..4
00
RX
1
CRC_OK
5..4
01
RX
1
FIFOFULL
5..4
10
RX
1
RSSI_IRQ
5..4
11
RX
1
FIFO_Int_Rx
3
0
TX
1
FIFOFULL
3
1
TX
1
TX_Stop
Table 81
In addition, IRQCFG0E allows several internal interrupts to be configured. See Table 82 below:
IRQCFG0E bits
Cfg
Internal Interrupt Control
7
0
Start FIFO fill when start pattern detected
7
1
Control FIFO with bit 6
6
0
Stop filling FIFO (if bit 7 is 0, this is Start Pattern Detect)
6
1
Start filling FIFO
5
0
Transmitting all pending bits in FIFO
5
1
All bits in FIFO transmitted
4
0
FIFO OK
4
1
FIFO overflow (write 1 to reset FIFO)
3
0
Disable RSSI interrupt (bit 2)
3
1
Enable RSSI interrupt (bit 2)
2
1
RF signal ≥ RSSI threshold
2
0
RF signal < RSSI Threshold
1
1
PLL not locked
1
0
PLL locked
0
1
PLL_LOCK signal disabled (bit 1 above), Pin 23 set high
0
0
PLL_LOCK signal enabled
Table 82
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 60 of 67
TRC105 - 10/16/12
MCFG0C bits 7..6 set the length of the FIFO as shown in Table 83. The length of the FIFO must be equal to or
greater than the maximum payload length set in PKTCFG1C, as discussed below.
MCFG0C bits 7..6
FIFO Length
00
16 bytes
01
32 bytes
10
48 bytes
11
64 bytes
Table 83
The integer value of MCFG0C bits 5..0 + 1 sets the FIFO interrupt threshold. When receiving in Packet data
mode, FIFO_Int_Rx is triggered when the number of bytes in the FIFO is equal to or greater than the threshold.
FIFO_Int_Tx is triggered when the number of bytes in the FIFO is equal to or less than the threshold value. Two
additional interrupts, nFIFOEMPY and FIFOFULL provide signaling that a packet transmission is complete or a
full packet has been received respectively.
Packet data mode formats are discussed in Section 3.9. Packet data mode options are configured in registers
PKTCFG1C through PKTCFG1F. Setting PKTCFG1C bit 7 to 1 selects Manchester encoding/decoding. Manchester encoding provides excellent DC-balance and other characteristics that support robust communications,
but effectively doubles the number of bits needed to transmit the packet payload. Scrambling provides adequate
DC-balance in many applications without doubling the number of bits in the payload. It is not necessary to enable
both Manchester encoding and scrambling. PKTCFG1C bits 6..0 configure the payload size (not including the
preamble and start pattern) in fixed format and maximum allowed length byte value in variable length and extended variable length formats. In a variable length format, a received packet with a length byte value greater than the
maximum allowed is discarded. PKTCFG1D bits 7..0 hold the node address byte used to identify a specific radio
in a network.
PKTCFG1D bits 7..0 hold the node address byte used to identify a specific radio in a network. PKTCFG1E bit 7
configures the basic packet format. Setting this bit to 0 selects the fixed-length format, and setting this bit to 1 selects the variable length format. PKTCFG1E bits 6..5 set the preamble length:
PKTCFG1E bits 6..5
Preamble Length
00
1 byte
01
2 bytes
10
3 bytes
11
4 bytes
Table 84
For most applications a preamble length of three or four bytes is recommended. PKTCFG1E bit 4 controls DCbalanced scrambling. Setting this bit to 1 enables scrambling. PKTCFG1E bit 3 controls CRC calculations. Setting
his bit to 1 enables CRC calculations. PKTCFG1E bits 2..1 configure node address filtering:
PKTCFG1E bits 2..1
Node Address Filtering
00
no filtering
01
only node address accepted
10
node address and 0x00 accepted
11
node address, 0x00 and 0xFF accepted
Table 85
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 61 of 67
TRC105 - 10/16/12
PKTCFG1E bit 0 is the result of the last CRC calculation. This bit is 1 when the CRC indicates no errors.
PKTCFG1F bit 7 controls CRC packet filtering. If this bit is set to 0, the FIFO is cleared automatically if the CRC
calculation on a received packet indicates an error. If set to 1, the FIFO data is preserved when the CRC calculation shows an error. PKTCFG1F bit 6 allows the FIFO to be written to or read when the TRC105 is in standby
mode. Setting this bit to 0 allows the FIFO to be written and setting this bit to 1 allows it to be read.
The following is a typical Packet data mode operating scenario. There are many other ways to configure this flexible data mode.
1. Switch to standby mode by setting MCFG00 bits 7..5 to 001.
2. Set the FIFO to a suitable size for the application in MCFG0C bits 7..6.
3. In PKTCFG1C set bit 7 to 0 to disable Manchester encoding and set the value in bits 6..0 to match
the FIFO size - 1.
4. Load the chosen node address into PKTCFG1D.
5. In PKTCFG1E set bit 7 to 1 to for variable length packets.
6. Set the preamble length in PKTCFG1E bits 6..5.
7. Set bit 4 in PKTCFG1E to 1 to enable DC-balanced scrambling.
8. Set bits 2..1 in PKTCFG1E to 10 to accept packets to this node address and 0x00 broadcasts.
9. Set bit 3 in PKTCFG1E to 1 to enable CRC calculations.
10. In PKTCFG1F set bit 7 to 0 to enable FIFO clear on CRC error.
11. Set the start pattern length in RXCFG12 bits 4..3.
12. Load the start pattern in registers SYNCFG16 up through SYNCFG19 as required.
13. Set IRQCFG0E bit 7 to 0. In receive, the FIFO will start filling when a start pattern is detected.
14. Set IRQCFG0D bit 7..6 to 00. In receive, IRQ0 will flag that a packet has been received with a good CRC
calculation and is ready to retrieve.
15. Set IRQCFG0D bit 3 to 1. In transmit, IRQ0 will clear to 0 when the FIFO is empty (optional).
16. Set IRQCFG0D bit 5..4 to 00. In receive, IRQ1 will signal the CRC is OK (optional).
17. Set IRQCFG0D bit 3 to 1. IRQ1 will flag when the last bit starts to be transmitted.
18. Load the operating frequency into register set MCFG06-MCFG08 or MCFG09-MCFG0B.
19. Select the register set to use by setting MCFG05 bit 0. A 0 value selects register set MCFG06-MCFG08
and a 1 value selects register set MCFG09-MCFG0B.
20. When ready to transmit, Set bit 6 to 0 in PKTCFG1F to enable FIFO write in standby mode.
21. Load the FIFO with the packet to be transmitted through the SPI port.
22. Place the TRC105 in synthesizer mode by setting MCFG00 bits 7..5 set to 010. Monitor the TRC105 Pin
23 to confirm PLL lock.
23. Place TRC103 in transmit mode by setting MCFG00 bits 7..5 set to 100. Monitor IRQ1. It sets when the
when the last bit starts to be transmitted. Allow one bit period for the last bit to be transmitted and then
switch to standby mode by setting MCFG00 bits 7..5 to 001.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 62 of 67
TRC105 - 10/16/12
24. When ready to receive, Place the TRC105 in synthesizer mode by setting MCFG00 bits 7..5 set to 010.
Monitor the TRC105 Pin 23 to confirm PLL lock.
25. Switch from synthesizer mode to receive mode by setting MCFG00 bits 7..5 to 011.
26. Monitor IRQ0. When an error free packet is received addressed to this node, IRQ0 will set.
27. Switch the TRC105 to standby mode by setting MCFG00 bits 7..5 to 001.
28. Set bit 6 to 1 in PKTCFG1F to enable FIFO read in standby mode.
29. Retrieve the received data from the FIFO through the SPI port.
30. From standby mode, enter another transmit cycle as outlined in steps 20 through 23, or enter
another receive cycle as outlined in steps 24 through 30.
6.7 Battery Power Management Configuration Values
Battery life can be greatly extended in TRC105 applications where transmissions from field nodes are infrequent,
or network communications can be concentrated into periodic time slots. For example, field nodes in many wireless alarm systems report operational status a few times a day, and can otherwise sleep unless an alarm condition occurs. Sensor networks that monitor parameters that change relatively slowly, such as air and soil temperature in agricultural settings, only need to transmit updates a few times an hour.
At room temperature the TRC105 draws a maximum of 1 µA in sleep mode, with a typical value of 100 nA. To
achieve minimum sleep mode current, nSS_CONFIG (Pin 14), SDI (Pin 17) and SCK (Pin 18) must be held logic
low, while nSS_DATA (Pin 15) must be held logic high. Also, the external connection to SDO (Pin 16) must be
configured as high impedance (tri-state or input). The TRC105 can go from sleep mode through standby mode
and synthesizer mode to transmit (or receive) mode in less than 6 ms. At a data rate of 33.33 kb/s, a 32 byte
packet with a 4 byte preamble and a 4 byte start pattern takes about 10 ms to transmit. Assume that the TRC105
then switches to receive mode for 1 second to listen for a response and returns to sleep. On the basis of reporting
every six hours, the ON to sleep duty cycle is about 1:21,259, greatly extending battery life over continuous
transmit-receive or even standby operation. RFM provides an Excel spreadsheet, battery_ life_ calculator.xls, in
the Application Notes section of www.RFM.com to support battery life for various operating scenarios.
The required timing accuracy for the microcontrollers in a sleep-cycled application depends on several things:

The required “time-stamp” accuracy of data reported by sleeping field nodes. R-C sleep mode timers built
into many microcontrollers have a tolerance of ±20% or more. Where more accurate time stamping is required, many microcontrollers can run on a watch crystal during sleep and achieve time stamp accuracies
better than 1 second per 24 hours.

If the base station and any routing nodes present in a network must sleep cycle in addition to the field
nodes, watch crystal control will usually be needed to keep all nodes accurately synchronized to the active time slots.

If the base station and any routing nodes present in a network can operate continuously (AC powered,
solar charged batteries, etc.) and a loose time stamp accuracy is OK, the microcontrollers in sleeping field
nodes can usually operated from internal low-accuracy R-C timers.
NOTE: The host microcontroller usually cannot be operated from the TRC105 buffered clock output if sleep cycling is planned. In sleep mode, the TRC105 buffered clock output is disabled, which will disable the microcontroller unless it is capable of automatically switching to an internal clock source when external clocking is lost.
TRC105 sleep related mode switching is configured in MCFG00 bits 7..5 as follows:
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 63 of 67
TRC105 - 10/16/12
MCFG bits 7..5
Operating Mode
000
sleep mode - all oscillators off
001
standby - crystal oscillator only on
010
synthesizer - crystal and PLL on
011
receive mode
100
transmit mode
Table 86
When switching from sleep mode to standby, the crystal oscillator will be active in no more than 5 ms. Switching
from standby to synthesizer mode, the PLL will lock in less than 0.5 ms. PLL lock can be monitored on Pin 23 of
the TRC105. The radio can then be switched to either transmit or receive mode. When switching from any other
mode back to sleep, the TRC105 will drop to its sleep mode current in less than 1 ms.
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 64 of 67
TRC105 - 10/16/12
7.0 Package Dimensions and Typical PCB Footprint - QFN-32
C
E
3 2
R F M
J
Y Y W W
T R C 1 0 5
A
1
K
H
I
F
D
B
G
M
Q
L
N
S
U
T
R
V
P la c e v ia to
g r o u n d in
e a c h c o rn e r.
W h ite a r e a
a r o u n d v ia is
s o ld e r m a s k .
O
P
Figure 25
Dimension
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
Minimum
4.95
4.95
0.00
0.70
0.20
0.30
3.00
3.00
Millimeters
Nominal Maximum
5.00
5.05
5.00
5.05
0.03
0.05
0.75
0.80
3.50
0.50
0.25
0.30
3.50
0.40
0.50
3.10
3.20
3.10
3.20
5.90
0.90
4.10
4.10
5.90
0.30
0.50
3.30
3.30
0.90
0.90
Minimum
0.195
0.195
0.000
0.028
0.008
0.012
0.118
0.118
Inches
Nominal
0.197
0.197
0.001
0.030
0.138
0.020
0.010
0.138
0.016
0.122
0.122
0.232
0.035
0.161
0.161
0.232
0.012
0.020
0.130
0.130
0.035
0.035
Maximum
0.199
0.199
0.002
0.031
0.012
0.020
0.126
0.126
Table 82
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 65 of 67
TRC105 - 10/16/12
8.0 Tape and Reel Dimensions
D
T
C O V E R
W
(C A R R IE R T A P E S IZ E )
T A P E S IZ E
K
B
A
O
C O V E R
P
O
O
T A P E
( P itc h )
D ir e c tio n o f F e e d
Figure 26
Dimension
mm
inches
minimum
nominal
maximum
minimum
nominal
maximum
AO
5.05
5.25
5.45
0.199
0.207
0.215
BO
5.05
5.25
5.45
0.199
0.207
0.215
D
-
330.2
-
-
13.0
-
KO
1.0
1.1
1.2
0.039
0.043
0.047
P
7.9
8.0
8.1
0.311
0.315
0.319
T
-
12.4
-
-
0.488
-
W
11.7
12.0
12.3
0.461
0.472
0.484
Table 83
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 66 of 67
TRC105 - 10/16/12
9.0 Solder Reflow Profile
TRC105 Lead Free IR Reflow Profile (MLP/TQFN Package)
Figure 27
Ventilator: Off
Speed: 17 cm/min
Zones
Upper
Lower
#1
380
380
#2
240
240
#3
320
320
#4
380
380
Table 84
Name Probe #
2749-3-1
Curve 1
Max. Temp. Reached,
t = 0 s to 449 s
Temp
Reached at
258
356.83
Time above 200 ºC
Reached at, Duration
276.41
111.99
Time above 217 ºC
Reached at, Duration
314.53
Max. Slope, T = 200 ºC to 217 ºC
Time above 260 ºC
Reached at, Duration
69.70
--
--
Max Slope, T < 200 ºC
Max Slope, T < 200 ºC
Slope, Reached at, Duration Slope, Reached at, Duration
5.00
38
Max. Slope, T = 217 ºC to 260 ºC
1
-11.00
409
1
Max. Slope, T > 260 ºC
Slope, Reached at, Duration Slope, Reached at, Duration Slope, Reached at, Duration Slope, Reached at, Duration Slope, Reached at, Duration Slope, Reached at, Duration
1.50
315
2
-5.00
387
1
1.50
315
2
-5.00
379
1
--
--
--
--
--
--
Table 85
www.RFM.com E-mail: [email protected]
© 2009-2012 by RF Monolithics, Inc.
Technical support +1.800.704.6079
Page 67 of 67
TRC105 - 10/16/12