TI CC2550RTK

CC2550
CC2550
Single Chip Low Cost Low Power RF Transmitter
Applications
• 2400-2483.5 MHz ISM/SRD band systems
• Consumer Electronics
• Wireless game controllers
• Wireless audio
Product Description
The CC2550 is a low cost true single chip 2.4
GHz transmitter designed for very low power
wireless applications. The circuit is intended
for the ISM (Industrial, Scientific and Medical)
and SRD (Short Range Device) frequency
band at 2400-2483.5 MHz.
The main operating parameters and the 64byte transmit FIFO of CC2550 can be controlled
via an SPI interface. In a typical system, the
CC2550 will be used together with a microcontroller and a few passive components.
The RF transmitter is integrated with a highly
configurable baseband modulator which has a
configurable data rate up to 500 kbps.
Performance can be increased by enabling a
Forward Error Correction option, which is
integrated in the modulator.
technology platform based on 0.18 µm CMOS
technology.
CC2550 is part of Chipcon’s 4th generation
The CC2550 provides extensive hardware
support for packet handling, data buffering and
burst transmissions.
This data sheet contains preliminary data, and supplementary data will be published at a later
date. Chipcon reserves the right to make changes at any time without notice in order to improve
design and supply the best possible product. The product is not fully qualified at this point.
Key Features
•
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•
Small size (QLP 4x4 mm package, 16
pins)
True single chip 2.4 GHz RF transmitter
Frequency range: 2400-2483.5 MHz
Programmable data rate up to 500 kbps
Low current consumption
Programmable output power up to +1 dBm
Very few external components: Totally onchip frequency synthesizer, no external
filters needed
Programmable baseband modulator
Ideal for multi-channel operation
Configurable packet handling hardware
Suitable for frequency hopping systems
due to a fast settling frequency synthesizer
Optional Forward Error Correction with
interleaving
64-byte TX data FIFO
Suited for systems compliant with EN 300
328 and EN 300 440 class 2 (Europe),
•
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PRELIMINARY Data Sheet (Rev.1.2)
FCC CFR47 Part 15 (US), and ARIB STDT66 (Japan)
Many powerful digital features allow a
high-performance RF system to be made
using an inexpensive microcontroller
Efficient SPI interface: All registers can be
programmed with one “burst” transfer
Integrated analog temperature sensor
Lead-free “green“ package
Flexible support for packet oriented
systems: On chip support for sync word
insertion, flexible packet length and
automatic CRC handling
OOK supported
FSK, GFSK and MSK supported.
Optional automatic whitening of data
Support for asynchronous transparent
transmit mode for backwards compatibility
with
existing
radio
communication
protocols
SWRS039A
Page 1 of 54
CC2550
Table of Contents
APPLICATIONS ...........................................................................................................................................1
PRODUCT DESCRIPTION.........................................................................................................................1
KEY FEATURES ..........................................................................................................................................1
TABLE OF CONTENTS ..............................................................................................................................2
ABBREVIATIONS........................................................................................................................................4
1
ABSOLUTE MAXIMUM RATINGS ..............................................................................................4
2
OPERATING CONDITIONS ..........................................................................................................5
3
GENERAL CHARACTERISTICS..................................................................................................5
4
ELECTRICAL SPECIFICATIONS ................................................................................................5
4.1
CURRENT CONSUMPTION .....................................................................................................................5
4.2
RF TRANSMIT SECTION ........................................................................................................................6
4.3
CRYSTAL OSCILLATOR .........................................................................................................................6
4.4
FREQUENCY SYNTHESIZER CHARACTERISTICS .....................................................................................7
4.5
ANALOG TEMPERATURE SENSOR .........................................................................................................7
4.6
DC CHARACTERISTICS .........................................................................................................................8
4.7
POWER ON RESET.................................................................................................................................8
5
PIN CONFIGURATION...................................................................................................................8
6
CIRCUIT DESCRIPTION ...............................................................................................................9
7
APPLICATION CIRCUIT .............................................................................................................10
8
CONFIGURATION OVERVIEW .................................................................................................12
9
CONFIGURATION SOFTWARE.................................................................................................13
10
4-WIRE SERIAL CONFIGURATION AND DATA INTERFACE ...........................................13
10.1 CHIP STATUS BYTE ............................................................................................................................15
10.2 REGISTERS ACCESS ............................................................................................................................15
10.3 SPI READ ...........................................................................................................................................16
10.4 COMMAND STROBES ..........................................................................................................................16
10.5 FIFO ACCESS .....................................................................................................................................16
10.6 PATABLE ACCESS ............................................................................................................................16
11
MICROCONTROLLER INTERFACE AND PIN CONFIGURATION ...................................17
11.1 CONFIGURATION INTERFACE ..............................................................................................................17
11.2 GENERAL CONTROL AND STATUS PINS ..............................................................................................17
12
DATA RATE PROGRAMMING...................................................................................................18
13
PACKET HANDLING HARDWARE SUPPORT .......................................................................18
13.1 DATA WHITENING ...............................................................................................................................18
13.2 PACKET FORMAT ................................................................................................................................19
13.3 PACKET HANDLING IN TRANSMIT MODE ............................................................................................21
14
MODULATION FORMATS ..........................................................................................................21
14.1 FREQUENCY SHIFT KEYING ................................................................................................................21
14.2 MINIMUM SHIFT KEYING....................................................................................................................21
14.3 AMPLITUDE MODULATION .................................................................................................................21
15
FORWARD ERROR CORRECTION WITH INTERLEAVING ..............................................22
15.1 FORWARD ERROR CORRECTION (FEC)...............................................................................................22
15.2 INTERLEAVING ...................................................................................................................................22
16
RADIO CONTROL.........................................................................................................................23
16.1 POWER-ON START-UP SEQUENCE ......................................................................................................23
16.2 CRYSTAL CONTROL ............................................................................................................................24
16.3 VOLTAGE REGULATOR CONTROL.......................................................................................................24
16.4 ACTIVE MODE ....................................................................................................................................25
16.5 TIMING ...............................................................................................................................................25
17
DATA FIFO .....................................................................................................................................25
18
FREQUENCY PROGRAMMING.................................................................................................26
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 2 of 54
CC2550
19
19.1
20
21
22
22.1
23
24
25
25.1
25.2
26
26.1
26.2
26.3
26.4
26.5
26.6
26.7
26.8
26.9
27
27.1
27.2
28
28.1
28.2
28.3
28.4
28.5
29
30
30.1
30.2
31
32
VCO ..................................................................................................................................................27
VCO AND PLL SELF-CALIBRATION ...................................................................................................27
VOLTAGE REGULATORS ..........................................................................................................27
OUTPUT POWER PROGRAMMING .........................................................................................28
CRYSTAL OSCILLATOR.............................................................................................................29
REFERENCE SIGNAL ...........................................................................................................................30
EXTERNAL RF MATCH ..............................................................................................................30
GENERAL PURPOSE / TEST OUTPUT CONTROL PINS ......................................................30
ASYNCHRONOUS AND SYNCHRONOUS SERIAL OPERATION .......................................32
ASYNCHRONOUS OPERATION..............................................................................................................32
SYNCHRONOUS SERIAL OPERATION ....................................................................................................32
SYSTEM CONSIDERATIONS AND GUIDELINES ..................................................................32
SRD REGULATIONS ............................................................................................................................32
FREQUENCY HOPPING AND MULTI-CHANNEL SYSTEMS .....................................................................32
WIDEBAND MODULATION NOT USING SPREAD SPECTRUM ................................................................33
DATA BURST TRANSMISSIONS............................................................................................................33
CONTINUOUS TRANSMISSIONS ...........................................................................................................33
SPECTRUM EFFICIENT MODULATION ..................................................................................................33
LOW COST SYSTEMS ..........................................................................................................................34
BATTERY OPERATED SYSTEMS ..........................................................................................................34
INCREASING OUTPUT POWER .............................................................................................................34
CONFIGURATION REGISTERS.................................................................................................34
CONFIGURATION REGISTER DETAILS .................................................................................................38
STATUS REGISTER DETAILS .................................................................................................................46
PACKAGE DESCRIPTION (QLP 16)..........................................................................................49
RECOMMENDED PCB LAYOUT FOR PACKAGE (QLP 16) .....................................................................50
PACKAGE THERMAL PROPERTIES ........................................................................................................50
SOLDERING INFORMATION..................................................................................................................50
TRAY SPECIFICATION ..........................................................................................................................51
CARRIER TAPE AND REEL SPECIFICATION ...........................................................................................51
ORDERING INFORMATION.......................................................................................................51
GENERAL INFORMATION.........................................................................................................51
DOCUMENT HISTORY .........................................................................................................................51
PRODUCT STATUS DEFINITIONS .........................................................................................................52
ADDRESS INFORMATION ..........................................................................................................53
TI WORLDWIDE TECHNICAL SUPPORT...............................................................................53
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 3 of 54
CC2550
Abbreviations
Abbreviations used in this data sheet are described below.
ACP
Adjacent Channel Power
MSK
ADC
Analog to Digital Converter
NA
Minimum Shift Keying
Not Applicable
AGC
Automatic Gain Control
LO
Local Oscillator
AMR
Automatic Meter Reading
OOK
On Off Keying
ARIB
Association of Radio Industries and Businesses
PA
Power Amplifier
ASK
Amplitude Shift Keying
PCB
Printed Circuit Board
BER
Bit Error Rate
PD
Power Down
BT
Bandwidth-Time product
PER
Packet Error Rate
CFR
Code of Federal Regulations
PLL
Phase Locked Loop
CRC
Cyclic Redundancy Check
QPSK
Quadrature Phase Shift Keying
DC
ESR
FCC
Direct Current
Equivalent Series Resistance
Federal Communications Commission
QLP
RF
RX
Quad Leadless Package
Radio Frequency
Receive, Receive Mode
FEC
Forward Error Correction
SMD
Surface Mount Device
FHSS
Frequency Hopping Spread Spectrum
SNR
Signal to Noise Ratio
FIFO
First-In-First-Out
SPI
Serial Peripheral Interface
FSK
Frequency Shift Keying
SRD
Short Range Device
GFSK
Gaussian shaped Frequency Shift Keying
TX
Transmit, Transmit Mode
I/Q
In-Phase/Quadrature
VCO
Voltage Controlled Oscillator
ISM
Industrial, Scientific and Medical
WLAN
Wireless Local Area Networks
LC
Inductor-Capacitor
XOSC
Crystal Oscillator
LO
Local Oscillator
XTAL
Crystal
MCU
Microcontroller Unit
1
Absolute Maximum Ratings
Under no circumstances must the absolute maximum ratings given in Table 1 be violated. Stress
exceeding one or more of the limiting values may cause permanent damage to the device.
Caution!
ESD
sensitive
device.
Precaution should be used when handling
the device in order to prevent permanent
damage.
Parameter
Min
Max
Units
Condition
Supply voltage
–0.3
3.6
V
Voltage on any digital pin
–0.3
VDD+0.3,
max 3.6
V
Voltage on the pins RF_P, RF_N
and DCOUPL
–0.3
2.0
V
Storage temperature range
–50
150
°C
Solder reflow temperature
260
°C
According to IPC/JEDEC J-STD-020C
ESD
<500
V
According to JEDEC STD 22, method A114,
Human Body Model
All supply pins must have the same voltage
Table 1: Absolute maximum ratings
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 4 of 54
CC2550
2
Operating Conditions
The operating conditions for CC2550 are listed Table 2 in below.
Parameter
Min
Max
Unit
Operating temperature
–40
85
°C
Operating supply voltage
1.8
3.6
V
Condition
All supply pins must have the same voltage
Table 2: Operating conditions
3
General Characteristics
Parameter
Min
Frequency range
2400
Data rate
Typ
Max
Unit
Condition/Note
2483.5
MHz
There will be spurious signals at n/2·crystal oscillator
frequency (n is an integer number). RF frequencies at
n/2·crystal oscillator frequency should therefore not be
used (e.g. 2405, 2418, 2444, 2457, 2470 and 2483 MHz
when using a 26 MHz crystal). Please refer to the CC2550
Errata Note for more details.
1.2
500
kbps
FSK
1.2
250
kbps
GFSK and OOK
26
500
kbps
(Shaped) MSK (also known as differential offset QPSK)
Optional Manchester encoding (halves the data rate).
Table 3: General characteristics
4
4.1
Electrical Specifications
Current Consumption
Tc = 25°C, VDD = 3.0 V if nothing else stated. All measurement results obtained using the CC2550EM reference design.
Parameter
Current consumption in power
down modes
Current consumption
Current consumption, TX states
Min
Typ
Max
Unit Condition
200
nA
Voltage regulator to digital part off (SLEEP state)
160
µA
Voltage regulator to digital part on, all other modules in power
down (XOFF state)
1.4
mA
Only voltage regulator to digital part and crystal oscillator running
(IDLE state)
7.3
mA
Only the frequency synthesizer running (after going from IDLE
until reaching TX state, and frequency calibration states)
11.2
mA
Transmit mode, –12 dBm output power (TX state)
14.7
mA
Transmit mode, -6 dBm output power (TX state)
19.4
mA
Transmit mode, 0 dBm output power (TX state)
21.3
mA
Transmit mode, +1 dBm output power (TX state)
Table 4: Current consumption
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 5 of 54
CC2550
4.2
RF Transmit Section
Tc = 25°C, VDD = 3.0 V, 0 dBm if nothing else stated. All measurement results obtained using the CC2550EM reference
design.
Parameter
Min
Typ
Differential load
impedance
Max
Unit
80 + j74
Ω
+1
dBm
Output power, highest
setting
Condition/Note
Differential impedance as seen from the RF-port (RF_P
and RF_N) towards the antenna. Follow the CC2550EM
reference design available from the TI and Chipcon
websites.
Output power is programmable and is available across the
entire frequency band.
Delivered to 50 Ω single-ended load via CC2550EM
reference RF matching network.
Output power, lowest
setting
–30
dBm
Output power is programmable and is available across the
entire frequency band.
Delivered to 50 Ω single-ended load via CC2550EM
reference RF matching network.
Adjacent channel
power
–19
dBc
1 MHz channel spacing (±1 MHz from carrier) and 500
kbps MSK.
Alternate channel
power
–39
dBc
1 MHz channel spacing (±2 MHz from carrier) and 500
kbps MSK.
Spurious emissions
25 MHz – 1 GHz
–36
dBm
47-74, 87.5-118, 174230, 470-862 MHz
–54
dBm
1800-1900 MHz
–47
dBm
Restricted band in Europe
At 2·RF and 3·RF
–41
dBm
Restricted bands in USA
Otherwise above 1
GHz
–30
dBm
Table 5: RF transmit parameters
4.3
Crystal Oscillator
Tc = 25°C, VDD = 3.0 V if nothing else stated.
Parameter
Crystal frequency
Tolerance
Min
Typ
Max
Unit
26
26
27
MHz
±40
ppm
Condition/Note
This is the total tolerance including a) initial tolerance, b) crystal
loading, c) aging and d) temperature dependence.
The acceptable crystal tolerance depends on RF frequency and
channel spacing / bandwidth.
ESR
Start-up time
100
300
Ω
µs
Measured on CC2550 EM reference design.
Table 6: Crystal oscillator parameters
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 6 of 54
CC2550
4.4
Frequency Synthesizer Characteristics
Tc = 25°C, VDD = 3.0 V if nothing else stated. All measurement results obtained using the CC2550EM reference design.
Parameter
Min
Typ
Max
Unit
Condition/Note
Programmed
frequency resolution
397
FXOSC/
16
2
427
Hz
26-27 MHz crystal.
Synthesizer frequency
tolerance
±40
ppm
Given by crystal used. Required accuracy (including
temperature and aging) depends on frequency band and
channel bandwidth / spacing.
RF carrier phase noise
–74
dBc/Hz
@ 50 kHz offset from carrier
–74
dBc/Hz
@ 100 kHz offset from carrier
–77
dBc/Hz
@ 200 kHz offset from carrier
–97
dBc/Hz
@ 1 MHz offset from carrier
–106
dBc/Hz
@ 2 MHz offset from carrier
–114
dBc/Hz
@ 5 MHz offset from carrier
–117
dBc/Hz
@ 10 MHz offset from carrier
88.4
µs
Time from leaving the IDLE state until arriving in the
FSTXON or TX state, when not performing calibration.
Crystal oscillator running.
XOSC
cycles
Calibration can be initiated manually or automatically
before entering or after leaving RX/TX.
ms
Min/typ/max time is for 27/26/26 MHz crystal frequency.
PLL turn-on / hop time
PLL calibration time
18739
0.69
0.72
0.72
Table 7: Frequency synthesizer parameters
4.5
Analog Temperature Sensor
The characteristics of the analog temperature sensor are listed in Table 8 below. Note that it is
necessary to write 0xBF to the PTEST register to use the analog temperature sensor in the IDLE
state.
Parameter
Min
Typ
Max
Unit
Output voltage at –40°C
0.660
V
Output voltage at 0°C
0.755
V
Output voltage at +40°C
0.859
V
Output voltage at +80°C
0.958
V
Temperature coefficient
Error in calculated
temperature, calibrated
2.54
-2
*
0
2
*
Condition/Note
mV/°C
Fitted from –20°C to +80°C
°C
From –20°C to +80°C when using 2.54 mV / °C,
after 1-point calibration at room temperature
*
The indicated minimum and maximum error with 1point calibration is based on simulated values for
typical process parameters
Current consumption
increase when enabled
0.3
mA
Table 8: Analog temperature sensor parameters
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 7 of 54
CC2550
4.6
DC Characteristics
Tc = 25°C if nothing else stated.
Digital Inputs/Outputs
Min
Max
Unit
Condition
Logic "0" input voltage
0
0.7
V
Logic "1" input voltage
VDD-0.7
VDD
V
Logic "0" output voltage
0
0.5
V
For up to 4 mA output current
Logic "1" output voltage
VDD-0.3
VDD
V
For up to 4 mA output current
Logic "0" input current
NA
-50
nA
Input equals 0 V
Logic "1" input current
NA
50
nA
Input equals VDD
Table 9: DC characteristics
4.7
Power On Reset
When the power supply complies with the requirements in Table 10 below, proper Power-OnReset functionality is guaranteed. Otherwise, the chip should be assumed to have unknown state
until transmitting an SRES strobe over the SPI interface. See Section 16.1 on page 23 for further
details.
Parameter
Min
Typ
Power-up ramp-up time.
Power off time
Max
Unit
Condition/Note
5
ms
From 0 V until reaching 1.8 V
ms
Minimum time between power off and power-on.
1
Table 10: Power-on reset requirements
AVDD
RBIAS
DGUARD
Pin Configuration
SI
5
16 15 14 13
SCLK 1
12 AVDD
SO (GDO1) 2
11 RF_N
DVDD 3
10 RF_P
DCOUPL 4
9 CSn
5
6
7
8
XOSC_Q1
AVDD
XOSC_Q2
GDO0 (ATEST)
GND
Exposed die
attach pad
Figure 1: Pinout top view
Note: The exposed die attach pad must be connected to a solid ground plane as this is the main
ground connection for the chip.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 8 of 54
CC2550
Pin #
Pin name
Pin type
Description
1
SCLK
Digital Input
Serial configuration interface, clock input
2
SO (GDO1)
Digital Output
Serial configuration interface, data output.
Optional general output pin when CSn is high
3
DVDD
Power (Digital)
1.8 - 3.6 V digital power supply for digital I/O’s and for the digital core
voltage regulator
4
DCOUPL
Power (Digital)
1.6 - 2.0 V digital power supply output for decoupling.
NOTE: This pin is intended for use with the CC2550 only. It can not be
used to provide supply voltage to other devices.
5
XOSC_Q1
Analog I/O
Crystal oscillator pin 1, or external clock input
6
AVDD
Power (Analog)
1.8 - 3.6 V analog power supply connection
7
XOSC_Q2
Analog I/O
Crystal oscillator pin 2
8
GDO0
Digital I/O
Digital output pin for general use:
•
•
•
•
(ATEST)
Test signals
FIFO status signals
Clock output, down-divided from XOSC
Serial input TX data
Also used as analog test I/O for prototype/production testing
9
CSn
Digital Input
Serial configuration interface, chip select
10
RF_P
RF Output
Positive RF output signal from PA
11
RF_N
RF Output
Negative RF output signal from PA
12
AVDD
Power (Analog)
1.8 - 3.6 V analog power supply connection
13
AVDD
Power (Analog)
1.8 - 3.6 V analog power supply connection
14
RBIAS
Analog I/O
External bias resistor for reference current
15
DGUARD
Power (Digital)
Power supply connection for digital noise isolation
16
SI
Digital Input
Serial configuration interface, data input
Table 11: Pinout overview
6
Circuit Description
BIAS
XOSC
DIGITAL
INTERFACE
TO MCU
TX FIFO
PA
PACKET
HANDLER
RF_N
FREQ
SYNTH
FEC /
INTERLEAVER
RF_P
MODULATOR
RADIO CONTROL
SCLK
SO (GDO1)
SI
CSn
GDO0 (ATEST)
RBIAS XOSC_Q1 XOSC_Q2
Figure 2: CC2550 simplified block diagram
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 9 of 54
CC2550
A simplified block diagram of CC2550 is shown
in Figure 2.
The CC2550 transmitter is based on direct
synthesis of the RF frequency.
The frequency synthesizer
completely on-chip LC VCO.
includes
a
A crystal is to be connected to XOSC_Q1 and
7
XOSC_Q2. The crystal oscillator generates the
reference frequency for the synthesizer, as
well as clocks for the digital part.
A 4-wire SPI serial interface is used for
configuration and data buffer access.
The digital baseband includes support for
channel configuration, packet handling and
data buffering.
Application Circuit
Only a few external components are required
for using the CC2550. The recommended
application circuit is shown in Figure 3. The
external components are described in Table
12, and typical values are given in Table 13.
13. The balun and LC filter component values
and their placement are important to keep the
performance
optimized.
It
is
highly
recommended to follow the CC2550EM
reference design.
Bias resistor
Crystal
The bias resistor R141 is used to set an
accurate bias current.
The crystal oscillator uses an external crystal
with two loading capacitors (C51 and C71).
See Section 22 on page 29 for details.
Balun and RF matching
C102, C112, L101 and L111 form a balun that
converts the differential RF signal on CC2550
to a single-ended RF signal. C101 and C111
are needed for DC blocking. Together with an
appropriate
LC
network,
the
balun
components also transform the impedance to
match a 50 Ω antenna (or cable). Component
values for the RF balun and LC network are
easily found using the SmartRF® Studio
software. Suggested values are listed in Table
Component
C41
C51/C71
Power supply decoupling
The power supply must be properly decoupled
close to the supply pins. Note that decoupling
capacitors are not shown in the application
circuit. The placement and the size of the
decoupling capacitors are very important to
achieve the optimum performance. The
CC2550EM reference design should be
followed closely.
Description
100 nF decoupling capacitor for on-chip voltage regulator to digital part
Crystal loading capacitors, see Section 22 on page 29 for details
C101/C111
RF balun DC blocking capacitors
C102/C112
RF balun/matching capacitors
C103/C104
RF LC filter/matching capacitors
L101/L111
RF balun/matching inductors (inexpensive multi-layer type)
L102
RF LC filter inductor (inexpensive multi-layer type)
R141
Resistor for internal bias current reference
XTAL
26-27 MHz crystal, see Section 22 on page 29 for details
Table 12: Overview of external components (excluding supply decoupling capacitors)
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 10 of 54
CC2550
1.8V-3.6V power supply
R141
1 SCLK
SO
(GDO1)
2 SO (GDO1)
Antenna
(50 Ohm)
AVDD
13
RBIAS 14
DGUARD 15
SCLK
CC2550
RF_N 11
C111
C112
C101
L102
C103
L101
C102
CSn 9
8 GDO0
6 AVDD
C41
7 XOSC_Q2
4DCOUPL
L111
AVDD 12
3 DVDD DIE ATTACH PAD:RF_P 10
5XOSC_Q1
Digital Inteface
SI 16
SI
C104
Alternative:
Folded dipole PCB
antenna (no external
components needed)
GDO0
(optional)
CSn
XTAL
C51
C71
Figure 3: Typical application and evaluation circuit (excluding supply decoupling capacitors)
Component
Value
Manufacturer
C41
100 nF±10%, 0402 X5R
Murata GRM15 series
C51
27 pF±5%, 0402 NP0
Murata GRM15 series
C71
27 pF±5%, 0402 NP0
Murata GRM15 series
C101
100 pF±5%, 0402 NP0
Murata GRM15 series
C102
1.0 pF±0.25pF, 0402 NP0
Murata GRM15 series
C103
1.8 pF±0.25pF, 0402 NP0
Murata GRM15 series
C104
1.5 pF±0.25pF, 0402 NP0
Murata GRM15 series
C111
100 pF±5%, 0402 NP0
Murata GRM15 series
C112
1.0 pF±0.25pF, 0402 NP0
Murata GRM15 series
L101
1.2 nH±0.3nH, 0402 monolithic
Murata LQG15 series
L102
1.2 nH±0.3nH, 0402 monolithic
Murata LQG15 series
L111
1.2 nH±0.3nH, 0402 monolithic
Murata LQG15 series
R141
56 kΩ±1%, 0402
Koa RK73 series
XTAL
26.0 MHz surface mount crystal
NDK, AT-41CD2
Table 13: Bill of Materials for the application circuit
In the CC2550EM reference design, LQG15
series inductors from Murata have been used.
Measurements have been performed with
multi-layer inductors from other manufacturers
(e.g. Würth) and the measurement results
were the same as when using the Murata part.
The Gerber files for the CC2550EM reference
design are available from the TI and Chipcon
websites.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 11 of 54
CC2550
8
Configuration Overview
CC2550 can be configured to achieve optimum
performance for many different applications.
Configuration is done using the SPI interface.
The following key parameters can be
programmed:
•
•
•
•
•
•
•
•
•
Power-down / power up mode
Crystal oscillator power-up / power – down
Transmit mode
RF channel selection
Data rate
Modulation format
RF output power
Data buffering with 64-byte transmit FIFO
Packet radio hardware support
•
•
Forward Error Correction with interleaving
Data Whitening
Details of each configuration register can be
found in Section 27, starting on page 34.
Figure 4 shows a simplified state diagram that
explains the main CC2550 states, together with
typical usage and current consumption. For
detailed information on controlling the CC2550
state machine, and a complete state diagram,
see Section 16, starting on page 23.
Figure 4: Simplified state diagram, with typical usage and current consumption
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 12 of 54
CC2550
9
Configuration Software
CC2550 can be configured using the SmartRF®
Studio software, available for download from
http://www.ti.com. The SmartRF® Studio
software is highly recommended for obtaining
optimum register settings, and for evaluating
performance and functionality. A screenshot of
the SmartRF® Studio user interface for CC2550
is shown in Figure 5.
Figure 5: SmartRF® Studio user interface
10
4-wire Serial Configuration and Data Interface
CC2550 is configured via a simple 4-wire SPIcompatible interface (SI, SO, SCLK and CSn)
where CC2550 is the slave. This interface is
also used to read and write buffered data. All
address and data transfer on the SPI interface
is done most significant bit first.
All transactions on the SPI interface start with
a header byte containing a read/write bit, a
burst access bit and a 6-bit address.
During address and data transfer, the CSn pin
(Chip Select, active low) must be kept low. If
CSn goes high during the access, the transfer
will be cancelled. The timing for the address
and data transfer on the SPI interface is shown
in Figure 6 with reference to Table 14.
When CSn goes low, the MCU must wait until
the CC2550 SO pin goes low before starting to
transfer the header byte. This indicates that
the voltage regulator has stabilized and the
crystal is running. Unless the chip is in the
SLEEP or XOFF states or an SRES command
strobe is issued, the SO pin will always go low
immediately after taking CSn low.
Figure 7 gives a brief overview of different
register access types possible.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 13 of 54
CC2550
tsp
tch
tcl
tsd
thd
tns
SCLK:
CSn:
Write to register:
X
0
A6
A5
A4
A3
A2
A1
A0
Hi-Z
S7
S6
S5
S4
S3
S2
S1
S0
SI
SO
X
D 7
W
S7
D 6
D 5
D 4
D 3
D 2
D 1
D 0
S6
S5
S4
S3
S2
S1
S0
D 2
D 1
W
W
W
W
W
W
X
W
S7
Hi-Z
Read from register:
SI
X
SO Hi-Z
1
A6
A5
A4
A3
A2
A1
A0
S7
S6
S5
S4
S3
S2
S1
S0
X
D 7
R
D 6
R
D 5
R
D 4
D 3
R
R
R
D 0
R
R
Hi-Z
Figure 6: Configuration registers write and read operations
Parameter
Description
fSCLK
SCLK frequency
Min
Max
Units
-
10
MHz
9
MHz
6.5
MHz
100 ns delay inserted between address byte and data byte (single access), or between
address and data, and between each data byte (burst access).
SCLK frequency, single access
No delay between address and data byte
SCLK frequency, burst access
No delay between address and data byte, or between data bytes
tsp,pd
CSn low to positive edge on SCLK, in power-down mode
200
-
µs
tsp
CSn low to positive edge on SCLK, in active mode
20
-
ns
tch
Clock high
50
-
ns
tcl
Clock low
50
-
ns
trise
Clock rise time
-
5
ns
tfall
Clock fall time
-
5
ns
tsd
Setup data (negative SCLK edge) to
positive edge on SCLK
Single access
55
-
ns
Burst access
76
-
ns
(tsd applies between address and data bytes, and
between data bytes)
thd
Hold data after positive edge on SCLK
20
-
ns
tns
Negative edge on SCLK to CSn high
20
-
ns
Table 14: SPI interface timing requirements
Figure 7: Register access types
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 14 of 54
CC2550
10.1 Chip Status Byte
When the header byte, data byte or command
strobe is sent on the SPI interface, the chip
status byte is sent by the CC2550 on the SO
pin. The status byte contains key status
signals, useful for the MCU. The first bit, s7, is
the CHIP_RDYn signal; this signal must go low
before the first positive edge of SCLK. The
CHIP_RDYn signal indicates that the crystal is
running and the regulated digital supply
voltage is stable.
should only be updated when the chip is in this
state. The TX state will be active when the
chip is transmitting.
The last four bits (3:0) in the status byte contains FIFO_BYTES_AVAILABLE. This field
contains the number of bytes free for writing
into
the
TX
FIFO.
When
FIFO_BYTES_AVAILABLE=15, 15 or more
bytes are free.
Table 15 gives a status byte summary.
Bits 6, 5 and 4 comprise the STATE value. This
value reflects the state of the chip. The XOSC
and power to the digital core is on in the IDLE
state, but all other modules are in power down.
The frequency and channel configuration
Bits
Name
Description
7
CHIP_RDYn
Stays high until power and crystal have stabilized. Should always be low when using
the SPI interface.
6:4
STATE[2:0]
Indicates the current main state machine mode
Value
000
State
Description
Idle
IDLE state
(Also reported for some transitional states instead
of SETTLING or CALIBRATE)
001
Not used
(RX)
Not used, included for software compatibility
with CC2500 transceiver
010
TX
Transmit mode
011
FSTXON
Fast TX ready
100
CALIBRATE
Frequency synthesizer calibration is running
101
SETTLING
PLL is settling
110
Not used
(RXFIFO_OVERFLOW)
Not used, included for software compatibility
with CC2500 transceiver
111
TXFIFO_UNDERFLOW
TX FIFO has underflowed. Acknowledge with
SFTX
3:0
FIFO_BYTES_AVAILABLE[3:0]
The number of free bytes in the TX FIFO. If FIFO_BYTES_AVAILABLE=15, it
indicates that 15 or more bytes are free.
Table 15: Status byte summary
10.2 Registers Access
The configuration registers on the CC2550 are
located on SPI addresses from 0x00 to 0x2F.
Table 24 on page 36 lists all configuration
registers. The detailed description of each
register is found in Section 27.1, starting on
page 38. All configuration registers can be
both written and read. The read/write bit
controls if the register should be written or
read. When writing to registers, the status byte
is sent on the SO pin each time a header byte
or data byte is transmitted on the SI pin.
When reading from registers, the status byte is
sent on the SO pin each time a header byte is
transmitted on the SI pin.
Registers with consecutive addresses can be
accessed in an efficient way by setting the
burst bit in the address header. The address
sets the start address in an internal address
counter. This counter is incremented by one
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 15 of 54
CC2550
each new byte (every 8 clock pulses). The
burst access is either a read or a write access
and must be terminated by setting CSn high.
For register addresses in the range 0x300x3D, the “burst” bit is used to select between
status registers and command strobes (see
below). The status registers can only be read.
Burst read is not available for status registers,
so they must be read one at a time.
Figure 8: SRES command strobe
10.5 FIFO Access
10.3 SPI Read
When reading register fields over the SPI
interface while the register fields are updated
by the radio hardware (e.g. MARCSTATE or
TXBYTES), there is a small, but finite,
probability that a single read from the register
is being corrupt. As an example, the probability
of any single read from TXBYTES being
corrupt, assuming the maximum data rate is
used, is approximately 80 ppm. Refer to the
CC2550 Errata Note for more details.
10.4 Command Strobes
Command strobes may be viewed as single
byte instructions to CC2550. By addressing a
command strobe register, internal sequences
will be started. These commands are used to
disable the crystal oscillator, enable transmit
mode, flush the TX FIFO etc. The 9 command
strobes are listed in Table 23 on page 35.
The command strobe registers are accessed
in the same way as for a register write
operation, but no data is transferred. That is,
only the R/W bit (set to 0), burst access (set to
0) and the six address bits (in the range 0x30
through 0x3D) are written.
When writing command strobes, the status
byte is sent on the SO pin.
A command strobe may be followed by any
other SPI access without pulling CSn high.
After issuing an SRES command strobe the
next command strobe can be issued when the
SO pin goes low as shown in Figure 8. The
command strobes are executed immediately,
with the exception of the SPWD and the SXOFF
strobes that are executed when CSn goes
high.
The 64-byte TX FIFO is accessed through the
0x3F address. When the read/write bit is zero,
the TX FIFO is accessed. The TX FIFO is
write-only.
The burst bit is used to determine if FIFO
access is single byte or a burst access. The
single byte access method expects address
with burst bit set to zero and one data byte.
After the data byte a new address is expected;
hence, CSn can remain low. The burst access
method expects one address byte and then
consecutive data bytes until terminating the
access by setting CSn high.
The following header bytes access the FIFO:
•
0x3F: Single byte access to TX FIFO
•
0x7F: Burst access to TX FIFO
When writing to the TX FIFO, the status byte
(see Section 10.1) is output for each new data
byte on SO, as shown in Figure 6. This status
byte can be used to detect TX FIFO underflow
while writing data to the TX FIFO. Note that
the status byte contains the number of bytes
free before writing the byte in progress to the
TX FIFO. When the last byte that fits in the TX
FIFO is transmitted to the SI pin, the status
byte received concurrently on the SO pin will
indicate that one byte is free in the TX FIFO.
The transmit FIFO may be flushed by issuing a
SFTX command strobe. The FIFO is cleared
when going to the SLEEP state.
10.6 PATABLE Access
The 0x3E address is used to access the
PATABLE, which is used for selecting PA
power control settings. The SPI expects up to
eight data bytes after receiving the address.
By programming the PATABLE, controlled PA
power ramp-up and ramp-down can be
achieved. See Section 21 on page 28 for
output power programming details.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 16 of 54
CC2550
The PATABLE is an 8-byte table that defines
the PA control settings to use for each of the
eight PA power values (selected by the 3-bit
value FREND0.PA_POWER). The table is
written and read from the lowest setting (0) to
the highest (7), one byte at a time. An index
counter is used to control the access to the
table. This counter is incremented each time a
byte is read or written to the table, and set to
the lowest index when CSn is high. When the
highest value is reached the counter restarts at
0.
If one byte is written to the PATABLE and this
value is to be read out then CSn must be set
high before the read access in order to set the
index counter back to zero.
Note that the content of the PATABLE is lost
when entering the SLEEP state.
The access to the PATABLE is either single
byte or burst access depending on the burst
bit. When using burst access the index counter
will count up; when reaching 7 the counter will
restart at 0. The read/write bit controls whether
the access is a write access (R/W=0) or a read
access (R/W=1).
11
Microcontroller Interface and Pin Configuration
In a typical system, CC2550 will interface to a
microcontroller. This microcontroller must be
able to:
• Write buffered data
pin is the SO pin in the SPI interface. The
default setting for GDO1/SO is 3-state output.
By selecting any other of the programming
options the GDO1/SO pin will become a
generic pin. When CSn is low, the pin will
always function as a normal SO pin.
• Read back status information via the 4-wire
SPI-bus configuration interface (SI, SO,
SCLK and CSn)
In the synchronous and asynchronous serial
modes, the GDO0 pin is used as a serial TX
data input pin while in transmit mode.
• Program CC2550 into different modes
11.1 Configuration Interface
The microcontroller uses four I/O pins for the
SPI configuration interface (SI, SO, SCLK and
CSn). The SPI is described in 13 on page 13.
11.2 General Control and Status Pins
The CC2550 has one dedicated configurable
pin and one shared pin that can output internal
status information useful for control software.
These pins can be used to generate interrupts
on the MCU. See Section 24 page 30 for more
details of the signals that can be programmed.
The dedicated pin is called GDO0. The shared
The GDO0 pin can also be used for an on-chip
analog temperature sensor. By measuring the
voltage on the GDO0 pin with an external ADC,
the
temperature
can
be
calculated.
Specifications for the temperature sensor are
found in Section 4.5 on page 7.
With default PTEST register setting (0x7F) the
temperature sensor output is only available
when the frequency synthesizer is enabled
(e.g. the MANCAL, FSTXON and TX states).
It is necessary to write 0xBF to the PTEST
register to use the analog temperature sensor
in the IDLE state. Before leaving the IDLE
state, the PTEST register should be restored to
its default value (0x7F).
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 17 of 54
CC2550
12
Data Rate Programming
The data rate used when transmitting is
programmed by the MDMCFG3.DRATE_M and
the
MDMCFG4.DRATE_E
configuration
registers. The data rate is given by the formula
below. As the formula shows, the programmed
data rate depends on the crystal frequency.
RDATA =
(256 + DRATE _ M ) ⋅ 2 DRATE _ E ⋅ f
2 28
XOSC
If DRATE_M is rounded to the nearest integer
and becomes 256, increment DRATE_E and
use DRATE_M=0.
The data rate can programmed from 1.2 kbps
to 500 kbps with a minimum step size of:
Data rate
start
[kbps]
Typical
data rate
[kbps]
Data rate
stop [kbps]
Data rate
step size
[kbps]
0.8
1.2/2.4
3.17
0.0062
3.17
4.8
6.35
0.0124
6.35
9.6
12.7
0.0248
12.7
19.6
25.4
0.0496
25.4
38.4
50.8
0.0992
50.8
76.8
101.6
0.1984
101.6
153.6
203.1
0.3967
203.1
250
406.3
0.7935
406.3
500
500
1.5869
The following approach can be used to find
suitable values for a given data rate:
⎢
⎛ R DATA ⋅ 2 20 ⎞⎥
⎟⎟⎥
DRATE _ E = ⎢log 2 ⎜⎜
⎝ f XOSC ⎠⎦⎥
⎣⎢
DRATE _ M =
R DATA ⋅ 2
− 256
f XOSC ⋅ 2 DRATE _ E
28
Table 16: Data rate step size
13
Packet Handling Hardware Support
The CC2550 has built-in hardware support for
packet oriented radio protocols.
In transmit mode, the packet handler will add
the following elements to the packet stored in
the TX FIFO:
•
•
•
•
•
A programmable number of preamble
bytes.
A two byte synchronization (sync) word.
Can be duplicated to give a 4-byte sync
word.
Optionally whiten the data with a PN9
sequence.
Optionally Interleave and Forward Error
Code the data.
Optionally compute and add a CRC
checksum over the data field.
In a system where CC2550 is used as the
transmitter and CC2500 as the receiver the
recommended setting is 4-byte preamble and
4-byte sync word except for 500 kbps data rate
where the recommended preamble length is 8
bytes.
13.1 Data whitening
From a radio perspective, the ideal over the air
data are random and DC free. This results in
the smoothest power distribution over the
occupied bandwidth. This also gives the
regulation loops in the receiver uniform
operation conditions (no data dependencies).
Real world data often contain long sequences
of zeros and ones. Performance can then be
improved by whitening the data before
transmitting, and de-whitening in the receiver.
With CC2550, in combination with a CC2500 at
the receiver end, this can be done
automatically
by
setting
PKTCTRL0
.WHITE_DATA=1. All data, except the
preamble and the sync word, are then XOR-ed
with a 9-bit pseudo-random (PN9) sequence
before being transmitted as shown in Figure 9.
At the receiver end, the data are XOR-ed with
the same pseudo-random sequence. This way,
the whitening is reversed, and the original data
appear in the receiver.
Data whitening can only be used when
PKTCTRL0.CC2400_EN = 0 (default).
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 18 of 54
CC2550
Figure 9: Data whitening in TX mode
•
13.2 Packet format
The format of the data packet can be
configured and consists of the following items
(see Figure 10):
•
•
Preamble
Synchronization word
•
•
•
Length byte or constant programmable
packet length
Optional Address byte
Payload
Optional 2 byte CRC
Data field
16/32 bits
8
bits
8
bits
8 x n bits
Legend:
Inserted automatically in TX,
processed and removed in RX.
CRC-16
Address field
8 x n bits
Length field
Preamble bits
(1010...1010)
Sync word
Optional data whitening
Optionally FEC encoded/decoded
Optional CRC-16 calculation
Optional user-provided fields processed in TX,
processed but not removed in RX.
Unprocessed user data (apart from FEC
and/or whitening)
16 bits
Figure 10: Packet format
The preamble pattern is an alternating
sequence of ones and zeros (01010101…).
The minimum length of the preamble is
programmable. When enabling TX, the
modulator will start transmitting the preamble.
When the programmed number of preamble
bytes has been transmitted, the modulator will
send the sync word and then data from the TX
FIFO if data is available. If the TX FIFO is
empty, the modulator will continue to send
preamble bytes until the first byte is written to
the TX FIFO. The modulator will then send the
sync word and then the data bytes. The
number of preamble bytes is programmed with
the MDMCFG1.NUM_PREAMBLE value.
The synchronization word is a two-byte value
set in the SYNC1 and SYNC0 registers. The
sync word provides byte synchronization of the
incoming packet. A one-byte synch word can
be emulated by setting the SYNC1 value to the
preamble pattern. It is also possible to emulate
a
32
bit
sync
word
by
using
MDMCFG2.SYNC_MODE=3 or 7. The sync word
will then be repeated twice.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 19 of 54
CC2550
CC2550 supports both fixed packet length
protocols and variable packet length protocols.
Variable or fixed packet length mode can be
used for packets up to 255 bytes. For longer
packets, infinite packet length mode must be
used.
Fixed packet length mode is selected by
setting PKTCTRL0.LENGTH_CONFIG=0. The
desired packet length is set by the PKTLEN
register.
In
variable
packet
length
mode,
PKTCTRL0.LENGTH_CONFIG=1, the packet
length is configured by the first byte after the
sync word. The packet length is defined as the
payload data, excluding the length byte and
the optional automatic CRC.
With PKTCTRL0.LENGTH_CONFIG=2, the
packet length is set to infinite and transmission
will continue until turned off manually. The
infinite mode can be turned off while a packet
is being transmitted. As described in the next
section, this can be used to support packet
formats with different length configuration than
natively supported by CC2550.
13.2.1 Arbitrary length field configuration
By utilizing the infinite packet length option,
arbitrary packet length is available. At the start
of the packet, the infinite mode must be active.
On the TX side, the PKTLEN register is set to
mod(length, 256). When less than 256
bytes remains of the packet the MCU disables
infinite packet length and activates fixed length
packets. When the internal byte counter
reaches the PKTLEN value, the transmission
ends. Automatic CRC appending/checking can
be used (by setting PKTCTRL0.CRC_EN to 1).
When for example a 600-byte packet is to be
transmitted, the MCU should do the following
(see also Figure 11):
•
Set PKTCTRL0.LENGTH_CONFIG=2 (10).
•
Pre-program the PKTLEN
mod(600,256)=88.
•
Transmit at least 345 bytes, for example
by filling the 64-byte TX FIFO six times
(384 bytes transmitted).
•
Set PKTCTRL0.LENGTH_CONFIG=0 (00).
•
The transmission ends when the packet
counter reaches 88. A total of 600 bytes
are transmitted.
register
to
Figure 11: Arbitrary length field configuration
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 20 of 54
CC2550
13.3 Packet Handling in Transmit Mode
The payload that is to be transmitted must be
written into the TX FIFO. The first byte written
must be the length byte when variable packet
length is enabled. The length byte has a value
equal to the payload of the packet (including
the optional address byte). If fixed packet
length is enabled, then the first byte written to
the TX FIFO is interpreted as the destination
address, if this feature is enabled in the device
that receives the packet.
The modulator will first send the programmed
number of preamble bytes. If data is available
in the TX FIFO, the modulator will send the
two-byte (optionally 4-byte) sync word and
then the payload in the TX FIFO. If CRC is
14
enabled, the checksum is calculated over all
the data pulled from the TX FIFO and the
result is sent as two extra bytes at the end of
the payload data.
If whitening is enabled, the length byte,
payload data and the two CRC bytes will be
whitened. This is done before the optional
FEC/Interleaver stage. Whitening is enabled
by setting PKTCTRL0.WHITE_DATA=1.
If FEC/Interleaving is enabled, the length byte,
payload data and the two CRC bytes will be
scrambled by the interleaver, and FEC
encoded before being modulated.
Modulation Formats
CC2550 supports amplitude, frequency and
phase shift modulation formats. The desired
modulation
format
is
set
in
the
MDMCFG2.MOD_FORMAT register.
Optionally, the data stream can be Manchester
coded by the modulator. This option is enabled
by setting MDMCFG2.MANCHESTER_EN=1.
Manchester encoding is not supported at the
same time as using the FEC/Interleaver
option.
14.1 Frequency Shift Keying
FSK can optionally be shaped by a Gaussian
filter with BT=1, producing a GFSK modulated
signal.
The frequency deviation is programmed with
the DEVIATION_M and DEVIATION_E values
in the DEVIATN register. The value has an
exponent/mantissa form, and the resultant
deviation is given by:
f dev =
f xosc
⋅ (8 + DEVIATION _ M ) ⋅ 2 DEVIATION _ E
217
The symbol encoding is shown in Table 17.
Format
Symbol
Coding
FSK\GFSK
‘0’
– Deviation
‘1’
+ Deviation
Table 17: Symbol encoding for FSK
modulation
14.2 Minimum Shift Keying
When using MSK1, the complete transmission
(preamble, sync word and payload) will be
MSK modulated.
Phase shifts are performed with a constant
transition time.
The fraction of a symbol period used to
change the phase can be modified with the
DEVIATN.DEVIATION_M setting. This is
equivalent to changing the shaping of the
symbol.
The MSK modulation format implemented in
inverts the sync word and data
compared to e.g. signal generators.
CC2550
14.3 Amplitude Modulation
The supported amplitude modulation On-Off
Keying (OOK) simply turns on or off the PA to
modulate 1 and 0 respectively.
1
Identical to offset QPSK with half-sine
shaping (data coding may differ)
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 21 of 54
CC2550
15
Forward Error Correction with Interleaving
15.1 Forward Error Correction (FEC)
15.2 Interleaving
CC2550 has built in support for Forward Error
Correction (FEC) that can be used with CC2500
Data received through real radio channels will
often experience burst errors due to
interference and time-varying signal strengths.
In order to increase the robustness to errors
spanning multiple bits, interleaving is used
when FEC is enabled. After de-interleaving, a
continuous span of errors in the received
stream will become single errors spread apart.
at the receiver end. To enable this option, set
MDMCFG1.FEC_EN to 1. FEC is employed on
the data field and CRC word in order to reduce
the gross bit error rate when operating near
the sensitivity limit. Redundancy is added to
the transmitted data in such a way that the
receiver can restore the original data in the
presence of some bit errors.
CC2550 employs matrix interleaving, which is
illustrated in Figure 12. The on-chip
interleaving and de-interleaving buffers are 4 x
4 matrices. In the transmitter, the data bits are
written into the rows of the matrix, whereas the
bit sequence to be transmitted is read from the
columns of the matrix and fed to the rate ½
convolutional coder. Conversely, in a CC2500
receiver, the received symbols are written into
the columns of the matrix, whereas the data
passed onto the convolutional decoder is read
from the rows of the matrix.
The use of FEC allows correct reception at a
lower SNR, thus extending communication
range. Alternatively, for a given SNR, using
FEC decreases the bit error rate (BER). As the
packet error rate (PER) is related to BER by:
PER = 1 − (1 − BER) packet _ length ,
a lower BER can be used to allow longer
packets, or a higher percentage of packets of
a given length, to be transmitted successfully.
Finally, in realistic ISM radio environments,
transient and time-varying phenomena will
produce occasional errors even in otherwise
good reception conditions. FEC will mask such
errors and, combined with interleaving of the
coded data, even correct relatively long
periods of faulty reception (burst errors).
When FEC and interleaving is used at least
one extra byte is required for trellis
termination. In addition, the amount of data
transmitted over the air must be a multiple of
the size of the interleaver buffer (two bytes).
The packet control hardware therefore
automatically inserts one or two extra bytes at
the end of the packet, so that the total length
of the data to be interleaved is an even
number. Note that these extra bytes are
invisible to the user, as they are removed
before the received packet enters the RX FIFO
in a CC2500.
The FEC scheme adopted for CC2550 is
convolutional coding, in which n bits are
generated based on k input bits and the m
most recent input bits, forming a code stream
able to withstand a certain number of bit errors
between each coding state (the m-bit window).
When FEC and interleaving is used the
minimum data payload is 2 bytes in fixed and
variable packet length mode.
The convolutional coder is a rate 1/2 code with
a constraint length of m=4. The coder codes
one input bit and produces two output bits;
hence, the effective data rate is halved.
3) Receiving
interleaved data
4) Passing on data
to decoder
Transmitter
Decoder
Demodulator
Encoder
TX
Data
2) Transmitting
interleaved data
Modulator
1) Storing coded
data
Note that for the CC2500 transceiver FEC is
only supported in fixed packet length mode
(PKTCTRL0.LENGTH_CONFIG=0).
RX
Data
Receiver
Figure 12: General principle of matrix interleaving
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 22 of 54
CC2550
16
Radio Control
SIDLE
SLEEP
0
SPWD
CAL_COMPLETE
MANCAL
3,4,5
CSn = 0
IDLE
1
SXOFF
SCAL
CSn = 0
XOFF
2
STX | SFSTXON
FS_WAKEUP
6,7
FS_AUTOCAL = 01
&
STX | SFSTXON
FS_AUTOCAL = 00 | 10 | 11
&
STX | SFSTXON
SFSTXON
FSTXON
18
CALIBRATE
8
CAL_COMPLETE
SETTLING
9,10,11
STX
STX
TXOFF_MODE = 01
TXOFF_MODE = 10
TX
19,20
TXFIFO_UNDERFLOW
TXOFF_MODE = 00
&
FS_AUTOCAL = 10 | 11
CALIBRATE
12
TXOFF_MODE = 00
&
FS_AUTOCAL = 00 | 01
TX_UNDERFLOW
22
SFTX
IDLE
1
Figure 13: Radio control state diagram
CC2550 has a built-in state machine that is
used to switch between different operation
states (modes). The change of state is done
either by using command strobes or by
internal events such as TX FIFO underflow.
A simplified state diagram, together with
typical usage and current consumption, is
shown in Figure 4 on page 12. The complete
radio control state diagram is shown in Figure
13. The numbers refer to the state number
readable in the MARCSTATE status register.
This functionality is primarily for test purposes.
16.1 Power-On Start-Up Sequence
When the power supply is turned on, the
system must be reset. One of the following two
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 23 of 54
CC2550
sequences must be followed: Automatic
power-on reset (POR) or manual reset.
XOSC and voltage regulator switched on
40 us
16.1.1 Automatic POR
A power-on reset circuit is included in the
CC2550. The minimum requirements stated in
Section 4.7 must be followed for the power-on
reset to function properly. The internal powerup sequence is completed when CHIP_RDYn
goes low. CHIP_RDYn is observed on the SO
pin after CSn is pulled low. See Section 10.1
for more details on CHIP_RDYn.
When the CC2550 reset is completed the chip
will be in the IDLE state and the crystal
oscillator running. If the chip has had sufficient
time for the crystal oscillator and voltage
regulator to stabilize after the power-on-reset,
the SO pin will go low immediately after taking
CSn low. If CSn is taken low before reset is
completed the SO pin will first go high,
indicating that the crystal oscillator and voltage
regulator is not stabilized, before going low as
shown in Figure 14.
CSn
SO
XOSC and voltage
regulator stabilized
Figure 14: Power-on reset
16.1.2 Manual Reset
CSn
SO
XOSC and voltage
regulator stabilized
SI
SRES
Figure 15: Power-on reset with SRES
Note that the above reset procedure is only
required just after the power supply is first
turned on. If the user wants to reset the
CC2550 after this, it is only necessary to issue
an SRES command strobe.
16.2 Crystal Control
The crystal oscillator is automatically turned on
when CSn goes low. It will be turned off if the
SXOFF or SPWD command strobes are issued;
the state machine then goes to XOFF or
SLEEP respectively. This can be done from
any state. The XOSC will be turned off when
CSn is released (goes high). The XOSC will be
automatically turned on again when CSn goes
low. The state machine will then go to the
IDLE state. The SO pin on the SPI interface
must be zero before the SPI interface is ready
to be used; as described in Section 10.1 on
page 15.
The other global reset possibility on CC2550 is
the SRES command strobe. By issuing this
strobe, all internal registers and states are set
to the default, IDLE state. The manual powerup sequence is as follows (see Figure 15):
Crystal oscillator start-up time depends on
crystal ESR and load capacitances. The
electrical specification for the crystal oscillator
can be found in Section 4.3 on page 6.
•
16.3 Voltage Regulator Control
Set SCLK=1 and SI=0, to avoid potential
problems with pin control mode (see
Section 11.2 on page 17).
•
Strobe CSn low / high.
•
Hold CSn high for at least 40 µs relative to
pulling CSn low
•
Pull CSn low and wait for SO to go low
(CHIP_RDYn).
•
Issue the SRES strobe on the SI line.
•
When SO goes low again, reset is
complete and the chip is in the IDLE state.
The voltage regulator to the digital core is
controlled by the radio controller. When the
chip enters the SLEEP state, which is the state
with the lowest current consumption, the
voltage regulator is disabled. This occurs after
CSn is released when a SPWD command
strobe has been sent on the SPI interface. The
chip is now in the SLEEP state. Setting CSn
low again will turn on the regulator and crystal
oscillator and make the chip enter the IDLE
state.
All CC2550 register values (with the exception
of the MCSM0.PO_TIMEOUT field) are lost in
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 24 of 54
CC2550
the SLEEP state. After the chip gets back to
the IDLE state, the registers will have default
(reset) contents and must be reprogrammed
over the SPI interface.
The SIDLE command strobe can always be
used to force the radio controller to go to the
IDLE state.
16.5 Timing
16.4 Active Mode
The active transmit mode is activated by the
MCU by using the STX command strobe.
The frequency synthesizer must be calibrated
regularly. CC2550 has one manual calibration
option (using the SCAL strobe), and three
automatic calibration options, controlled by the
MCSM0.FS_AUTOCAL setting:
•
Calibrate when going from IDLE to TX
(or FSTXON)
•
Calibrate when going from TX to IDLE
•
Calibrate every fourth time when going
from TX to IDLE
The calibration takes a constant number of
XOSC cycles (see Table 18 for timing details).
When TX is active, the chip will remain in the
TX state until the current packet has been
successfully transmitted. Then the state will
change
as
indicated
by
the
MCSM1.TXOFF_MODE setting. The possible
destinations are:
17
•
IDLE
•
FSTXON: Frequency synthesizer on
and ready at the TX frequency.
Activate TX with STX.
•
TX: Start sending preambles
The radio controller controls most timing in
CC2550, such as synthesizer calibration and
PLL lock. Timing from IDLE to TX is constant,
dependent on the auto calibration setting. The
calibration time is constant 18739 clock
periods. Table 18 shows timing in crystal clock
cycles for key state transitions.
Power on time and XOSC start-up times are
variable, but within the limits stated in Table 6.
Note that in a frequency hopping spread
spectrum or a multi-channel protocol the
calibration time can be reduced from 721 µs to
approximately 150 µs. This is explained in
Section 26.2.
Description
XOSC
periods
26 MHz
crystal
Idle to TX/FSTXON, no calibration
2298
88.4 µs
Idle to TX/FSTXON, with calibration
~21037
809 µs
TX to IDLE, no calibration
2
0.1 µs
TX to IDLE, including calibration
~18739
721 µs
Manual calibration
~18739
721 µs
Table 18: State transition timing
Data FIFO
The CC2550 contains a 64 byte FIFO for data
to be transmitted. The SPI interface is used for
writing to the TX FIFO. Section 10.5 contains
details on the SPI FIFO access. The FIFO
controller will detect underflow in the TX FIFO.
When writing to the TX FIFO it is the
responsibility of the MCU to avoid TX FIFO
overflow. A TX FIFO overflow will result in an
error in the TX FIFO content.
The chip status byte that is available on the SO
pin while transferring the SPI address contains
the fill grade of the TX FIFO. Section 10.1 on
page 15 contains more details on this.
The number of bytes in the TX FIFO can also
be read from the TXBYTES.NUM_TXBYTES
status register.
The 4-bit FIFOTHR.FIFO_THR setting is used
to program the FIFO threshold point. Table 19
lists the 16 FIFO_THR settings and the
corresponding thresholds for the TX FIFO.
A flag will assert when the number of bytes in
the FIFO is equal to or higher than the
programmed threshold. The flag is used to
generate the FIFO status signals that can be
viewed on the GDO pins (see Section 24 on
page 30).
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 25 of 54
CC2550
Figure 17 shows the number of bytes in the TX
FIFO when the threshold flag toggles, in the
case of FIFO_THR=13. Figure 16 shows the
flag as the FIFO is filled above the threshold,
and then drained below.
FIFO_THR
Bytes in TX FIFO
0 (0000)
61
1 (0001)
57
2 (0010)
53
3 (0011)
49
4 (0100)
45
5 (0101)
41
6 (0110)
37
7 (0111)
33
8 (1000)
29
9 (1001)
25
10 (1010)
21
11 (1011)
17
12 (1100)
13
13 (1101)
9
14 (1110)
5
15 (1111)
1
NUM_TXBYTES
6
7
8
9 10 9
8
7
6
GDO
Figure 16: FIFO_THR=13 vs. number of bytes
in FIFO (GDOx_CFG=0x02)
FIFO_THR=13
Underflow
margin
8 bytes
TXFIFO
Figure 17: Example of FIFO at threshold
Table 19: FIFO_THR settings and the
corresponding FIFO thresholds
18
Frequency Programming
The frequency programming in CC2550 is
designed to minimize the programming
needed in a channel-oriented system.
To set up a system with channel numbers, the
desired channel spacing is programmed with
the
MDMCFG0.CHANSPC_M
and
MDMCFG1.CHANSPC_E registers. The channel
spacing registers are mantissa and exponent
respectively.
f carrier =
(
The base or start frequency is set by the 24 bit
frequency word located in the FREQ2, FREQ1
and FREQ0 registers. This word will typically
be set to the centre of the lowest channel
frequency that is to be used.
The desired channel number is programmed
with the 8-bit channel number register,
CHANNR.CHAN, which is multiplied by the
channel offset. The resultant carrier frequency
is given by:
(
f XOSC
⋅ FREQ + CHAN ⋅ (256 + CHANSPC _ M ) ⋅ 2 CHANSPC _ E −2
16
2
With a 26 MHz crystal the maximum channel
spacing is 405 kHz. To get e.g. 1 MHz channel
spacing one solution is to use 333 kHz
))
channel spacing and select each third channel
in CHANNR.CHAN.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 26 of 54
CC2550
If any frequency programming register is
altered when the frequency synthesizer is
running, the synthesizer may give an
19
VCO
The VCO is completely integrated on-chip.
19.1 VCO and PLL Self-Calibration
The VCO characteristics will vary with
temperature and supply voltage changes, as
well as the desired operating frequency. In
order to ensure reliable operation, CC2550
includes frequency synthesizer self-calibration
circuitry. This calibration should be done
regularly, and must be performed after turning
on power and before using a new frequency
(or channel). The number of XOSC cycles for
completing the PLL calibration is given in
Table 18 on page 25.
The calibration can be initiated automatically
or manually. The synthesizer can be
automatically calibrated each time the
synthesizer is turned on, or each time the
synthesizer is turned off. This is configured
with the MCSM0.FS_AUTOCAL register setting.
20
undesired response. Hence, the frequency
programming should only be updated when
the radio is in the IDLE state.
In manual mode, the calibration is initiated
when the SCAL command strobe is activated
in the IDLE mode.
The calibration values are not maintained in
sleep mode. Therefore, the CC2550 must be
recalibrated
after
reprogramming
the
configuration registers when the chip has been
in the SLEEP state.
To check that the PLL is in lock the user can
program register IOCFGx.GDOx_CFG to 0x0A
and use the lock detector output available on
the GDOx pin as an interrupt for the MCU (x =
0,1 or 2). A positive transition on the GDOx pin
means that the PLL is in lock. As an alternative
the user can read register FSCAL1. The PLL is
in lock if the register content is different from
0x3F. For more robust operation the source
code could include a check so that the PLL is
re-calibrated until PLL lock is achieved if the
PLL does not lock the first time.
Voltage Regulators
CC2550 contains several on-chip linear voltage
regulators, which generate the supply voltage
needed by low-voltage modules. These
voltage regulators are invisible to the user, and
can be viewed as integral parts of the various
modules. The user must however make sure
that the absolute maximum ratings and
required pin voltages in Table 1 and Table 11
are not exceeded. The voltage regulator for
the digital core requires one external
decoupling capacitor.
If the chip is programmed to enter power-down
mode, (SPWD strobe issued), the power will be
turned off after CSn goes high. The power and
crystal oscillator will be turned on again when
CSn goes low.
The voltage regulator output should only be
used for driving the CC2550.
Setting the CSn pin low turns on the voltage
regulator to the digital core and starts the
crystal oscillator. The SO pin on the SPI
interface must go low before using the serial
interface (setup time is given in Table 14).
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 27 of 54
CC2550
21
Output Power Programming
The RF output power level from the device has
two levels of programmability, as illustrated in
Figure 18. Firstly, the special PATABLE
register can hold up to eight user selected
output power settings. Secondly, the 3-bit
FREND0.PA_POWER
value
selects
the
PATABLE entry to use. This two-level
functionality provides flexible PA power ramp
up and ramp down at the start and end of
transmission. All the PA power settings in the
PATABLE from index 0 up to the
FREND0.PA_POWER value are used.
The power ramping at the start and at the end
of a packet can be turned off by setting
FREND0.PA_POWER
to
0
and
then
programming the desired output power to
index 0 in the PATABLE.
Table 20 contains recommended PATABLE
settings for various output levels and
frequency bands. See Section 10.6 on page
16 for PATABLE programming details.
PATABLE must be programmed in burst mode
if you want to write to other entries than
PATABLE[0].
PATABLE(7)[7:0]
PATABLE(6)[7:0]
The PA uses this
setting.
PATABLE(5)[7:0]
PATABLE(4)[7:0]
PATABLE(3)[7:0]
PATABLE(2)[7:0]
PATABLE(1)[7:0]
Settings 0 to PA_POWER are
used during ramp-up at start of
transmission and ramp-down at
end of transmission, and for
OOK modulation.
PATABLE(0)[7:0]
Index into PATABLE(7:0)
e.g 6
PA_POWER[2:0]
in FREND0 register
The SmartRF® Studio software
should be used to obtain optimum
PATABLE settings for various
output powers.
Figure 18: PA_POWER and PATABLE
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 28 of 54
CC2550
Output power, typical,
o
+25 C, 3.0 V [dBm]
PATABLE
value
Current consumption,
typical [mA]
(–55 or less)
0x00
8.0
–30
0x44
9.3
–28
0x41
9.2
–26
0x43
9.7
–24
0x84
9.8
–22
0x82
9.7
–20
0x47
10.0
–18
0xC8
11.6
–16
0x85
10.2
–14
0x59
11.6
–12
0xC6
11.2
–10
0x97
12.0
–8
0xD6
12.9
–6
0x7F
14.7
–4
0xA9
16.2
–2
0xBF
18.1
0
0xEE
19.4
1
0xFF
21.3
Table 20: Optimum PATABLE settings for various output power levels
22
Crystal Oscillator
A crystal in the frequency range 26-27 MHz
must be connected between the XOSC_Q1
and XOSC_Q2 pins. The oscillator is designed
for parallel mode operation of the crystal. In
addition, loading capacitors (C51 and C71) for
the crystal are required. The loading capacitor
values depend on the total load capacitance,
CL, specified for the crystal. The total load
capacitance seen between the crystal
terminals should equal CL for the crystal to
oscillate at the specified frequency.
CL =
1
1
1
+
C 51 C 71
The crystal oscillator circuit is shown in Figure
19. Typical component values for different
values of CL are given in Table 21.
The crystal oscillator is amplitude regulated.
This means that a high current is used to start
up the oscillations. When the amplitude builds
up, the current is reduced to what is necessary
to maintain approximately 0.4 Vpp signal
swing. This ensures a fast start-up, and keeps
the drive level to a minimum. The ESR of the
crystal should be within the specification in
order to ensure a reliable start-up (see Section
4.3 on page 6).
+ C parasitic
XOSC_Q1
The parasitic capacitance is constituted by pin
input capacitance and PCB stray capacitance.
Total parasitic capacitance is typically 2.5 pF.
XOSC_Q2
XTAL
C51
C71
Figure 19: Crystal oscillator circuit
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 29 of 54
CC2550
Component
CL= 10pF
CL=13pF
CL=16pF
C51
15 pF
22 pF
27 pF
C71
15 pF
22 pF
27 pF
Table 21: Crystal oscillator component values
22.1 Reference Signal
The chip can alternatively be operated with a
reference signal from 26 to 27 MHz instead of
a crystal. This input clock can either be a fullswing digital signal (0 V to VDD) or a sine
wave of maximum 1 V peak-peak amplitude.
23
The reference signal must be connected to the
XOSC_Q1 input. The sine wave must be
connected to XOSC_Q1 using a serial
capacitor. The XOSC_Q2 line must be left unconnected. C51 and C71 can be omitted when
using a reference signal
External RF Match
The balanced RF output of CC2550 is designed
for a simple, low-cost matching and balun
network on the printed circuit board. A few
passive external components ensure proper
matching.
Although CC2550 has a balanced RF output,
the chip can be connected to a single-ended
antenna with few external low cost capacitors
and inductors.
differential impedance as seen from the RFport (RF_P and RF_N) towards the antenna:
Zout = 80 + j74 Ω
To ensure optimal matching of the CC2550
differential output it is highly recommended to
follow the CC2550EM reference designs as
closely as possible. Gerber files for the
reference designs are available for download
from the TI and Chipcon websites.
The
passive
matching/filtering
network
connected to CC2550 should have the following
24
General Purpose / Test Output Control Pins
The two digital output pins GDO0 and GDO1 are
general control pins. Their functions are
programmed by IOCFG0.GDO0_CFG and
IOCFG1.GDO1_CFG respectively. Table 22
shows the different signals that can be
monitored on the GDO pins. These signals can
be used as an interrupt to the MCU. GDO1 is
the same pin as the SO pin on the SPI
interface, thus the output programmed on this
pin will only be valid when CSn is high. The
default value for GDO1 is 3-stated, which is
useful when the SPI interface is shared with
other devices.
The default value for GDO0 is a 135-141 kHz
clock output (XOSC frequency divided by 192).
Since the XOSC is turned on at power-onreset, this can be used to clock the MCU in
systems with only one crystal. When the MCU
is up and running, it can change the clock
frequency by writing to IOCFG0.GDO0_CFG.
An on-chip analog temperature sensor is
enabled by writing the value 128 (0x80h) to the
IOCFG0.GDO0_CFG register. The voltage on
the GDO0 pin is then proportional to
temperature. See Section 4.5 on page 7 for
temperature sensor specifications.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 30 of 54
CC2550
GDOx_CFG[5:0]
0 (0x00)
1 (0x01)
2 (0x02)
3 (0x03)
4 (0x04)
5 (0x05)
6 (0x06)
7 (0x07)
8 (0x08)
9 (0x09)
10 (0x0A)
11 (0x0B)
12 (0x0C)
13 (0x0D)
14 (0x0E)
15 (0x0F)
16 (0x10)
17 (0x11)
18 (0x12)
19 (0x13)
20 (0x14)
21 (0x15)
22 (0x16)
23 (0x17)
24 (0x18)
25 (0x19)
26 (0x1A)
27 (0x1B)
28 (0x1C)
29 (0x1D)
30 (0x1E)
31 (0x1F)
32 (0x20)
33 (0x21)
34 (0x22)
35 (0x23)
36 (0x24)
37 (0x25)
38 (0x26)
39 (0x27)
40 (0x28)
41 (0x29)
42 (0x2A)
43 (0x2B)
44 (0x2C)
45 (0x2D)
46 (0x2E)
47 (0x2F)
48 (0x30)
49 (0x31)
50 (0x32)
51 (0x33)
52 (0x34)
53 (0x35)
54 (0x36)
55 (0x37)
56 (0x38)
57 (0x39)
58 (0x3A)
59 (0x3B)
60 (0x3C)
61 (0x3D)
62 (0x3E)
63 (0x3F)
Description
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Associated with the TX FIFO: Asserts when the TX FIFO is filled at or above TXFIFO_THR. De-asserts when the TX
FIFO is below TXFIFO_THR.
Associated to the TX FIFO: Asserts when TX FIFO is full. De-asserts when the TX FIFO is drained below
TXFIFO_THR.
Reserved – defined on the transceiver version.
Asserts when the TX FIFO has underflowed. De-asserts when the FIFO is flushed.
Asserts when sync word has been sent, and de-asserts at the end of the packet. The pin will also de-assert if the TX
FIFO underflows.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Lock detector output. The PLL is in lock if the lock detector output has a positive transition or is constantly logic high. To
check for PLL lock the lock detector output should be used as an interrupt for the MCU.
Serial Clock. Synchronous to the data in synchronous serial mode.
Data is set up on the falling edge and is read on the rising edge of SERIAL_CLK when GDOx_INV=0.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
PA_PD. Note: PA_PD will have the same signal level in SLEEP and TX states. To control an external PA in applications
where the SLEEP state is used it is recommended to use address 47 (0x2F).
Reserved – defined on the transceiver version.
Reserved – defined on the transceiver version.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
Reserved – used for test.
CHIP_RDY
Reserved – used for test.
XOSC_STABLE
Reserved – used for test.
GDO0_Z_EN_N. When this output is 0, GDO0 is configured as input (for serial TX data).
High impedance (3-state)
HW to 0 (HW1 achieved with _INV signal). Can be used to control an external PA
CLK_XOSC/1
CLK_XOSC/1.5
CLK_XOSC/2
CLK_XOSC/3
CLK_XOSC/4
CLK_XOSC/6
CLK_XOSC/8
Note: There are 2 GDO pins, but only one CLK_XOSC/n can be selected as an output at any
CLK_XOSC/12
time. If CLK_XOSC/n is to be monitored on one of the GDO pins, the other GDO pin must be
CLK_XOSC/16
configured to a value less than 0x30. The GDO0 default value is CLK_XOSC/192.
CLK_XOSC/24
CLK_XOSC/32
CLK_XOSC/48
CLK_XOSC/64
CLK_XOSC/96
CLK_XOSC/128
CLK_XOSC/192
Table 22: GDOx signal selection (x = 0 or 1)
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 31 of 54
CC2550
25
Asynchronous and Synchronous Serial Operation
Several features and modes of operation have
been included in the CC2550 to provide
backward compatibility with previous Chipcon
products and other existing RF communication
systems. For new systems, it is recommended
to use the built-in packet handling features, as
they can give more robust communication,
significantly offload the microcontroller and
simplify software development.
25.1 Asynchronous operation
For backward compatibility with systems
already using the asynchronous data transfer
from other Chipcon products, asynchronous
transfer is also included in CC2550. When
asynchronous transfer is enabled, several of
the support mechanisms for the MCU that are
included in CC2550 will be disabled, such as
packet handling hardware, buffering in the
FIFO and so on. The asynchronous transfer
mode does not allow the use of the data
whitener, interleaver and FEC.
Only FSK, GFSK and OOK are supported for
asynchronous transfer.
Setting
PKTCTRL0.PKT_FORMAT
to
3
enables asynchronous transparent (serial)
mode.
In TX, the GDO0 pin is used for data input (TX
data).
The MCU must control start and stop of
transmit with the STX and SIDLE strobes.
The CC2550 modulator samples the level of the
asynchronous input 8 times faster than the
programmed data rate. The timing requirement
for the asynchronous stream is that the error in
the bit period must be less than one eighth of
the programmed data rate.
25.2 Synchronous serial operation
Setting
PKTCTRL0.PKT_FORMAT
to
1
enables synchronous serial operation mode. In
this operational mode the data must be NRZ
encoded (MDMCFG2.MANCHESTER_EN=0). In
synchronous serial operation mode, data is
transferred on a two wire serial interface. The
CC2550 provides a clock that is used to set up
new data on the data input line. Data input (TX
data) is the GDO0 pin. This pin will
automatically be configured as an input when
TX is active.
Preamble and sync word insertion may or may
not be active, dependent on the sync mode set
by the MDMCFG3.SYNC_MODE. If preamble and
sync word is disabled, all other packet handler
features and FEC should also be disabled.
The MCU must then handle preamble and
sync word insertion in software. If preamble
and sync word insertion is left on, all packet
handling features and FEC can be used. The
CC2550 will insert the preamble and sync word
and the MCU will only provide the data
payload.
This
is
equivalent
to
the
recommended FIFO operation mode.
26 System considerations and Guidelines
26.1 SRD Regulations
International regulations and national laws
regulate the use of radio receivers and
transmitters. Short Range Devices (SRDs) for
license free operation are allowed to operate
in the 2.45 GHz bands worldwide. The most
important regulations are EN 300 440 and EN
300 328 (Europe), FCC CFR47 part 15.247
and 15.249 (USA), and ARIB STD-T66
(Japan). A summary of the most important
aspects of these regulations can be found in
Application Note AN032 SRD regulations for
license-free transceiver operation in the 2.4
GHz band, available from the TI and Chipcon
websites.
Please note that compliance with regulations
is
dependent
on
complete
system
performance. It is the customer’s responsibility
to ensure that the system complies with
regulations.
26.2 Frequency Hopping
Channel Systems
and
Multi-
The 2.400 – 2.4835 GHz band is shared by
many systems both in industrial, office and
home
environments.
It
is
therefore
recommended to use frequency hopping
spread spectrum (FHSS) or a multi-channel
protocol because the frequency diversity
makes the system more robust with respect to
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 32 of 54
CC2550
interference from other systems operating in
the same frequency band. FHSS also combats
multipath fading.
CC2550 is highly suited for FHSS or multichannel systems due to its agile frequency
synthesizer and effective communication
interface. Using the packet handling support
and data buffering is also beneficial in such
systems as these features will significantly
offload the host controller.
Charge pump current, VCO current and VCO
capacitance array calibration data is required
for each frequency when implementing
frequency hopping for CC2550. There are 3
ways of obtaining the calibration data from the
chip:
1) Frequency hopping with calibration for each
hop. The PLL calibration time is approximately
720 µs.
2) Fast frequency hopping without calibration
for each hop can be done by calibrating each
frequency at startup and saving the resulting
FSCAL3, FSCAL2 and FSCAL1 register values
in MCU memory. Between each frequency
hop, the calibration process can then be
replaced by writing the FSCAL3, FSCAL2 and
FSCAL1 register values corresponding to the
next RF frequency. The PLL turn on time is
approximately 90 µs.
3) Run calibration on a single frequency at
startup. Next write 0 to FSCAL3[5:4] to
disable the charge pump calibration. After
writing to FSCAL3[5:4] strobe SRX (or STX)
with MCSM0.FS_AUTOCAL = 1 for each new
frequency hop. That is, VCO current and VCO
capacitance calibration is done but not charge
pump current calibration. When charge pump
current calibration is disabled the calibration
time is reduced from approximately 720 µs to
approximately 150 µs.
There is a trade off between blanking time and
memory space needed for storing calibration
data in non-volatile memory. Solution 2) above
gives the shortest blanking interval, but
requires more memory space to store
calibration
values.
Solution
3)
gives
approximately 570 µs smaller blanking interval
than solution 1).
26.3 Wideband Modulation
Spread Spectrum
not
Using
A maximum peak output power of 1 W (+30
dBm) is allowed if the 6 dB bandwidth of the
modulated signal exceeds 500 kHz. In
addition, the peak power spectral density
conducted to the antenna shall not be greater
than +8 dBm in any 3 kHz band.
Operating at high data rates and high
frequency separation, the CC2550 is suited for
systems targeting compliance with digital
modulation systems as defined by FCC part
15.247. An external power amplifier is needed
to increase the output above +1 dBm.
26.4 Data Burst Transmissions
The high maximum data rate of CC2550 opens
up for burst transmissions. A low average data
rate link (e.g. 10 kbps), can be realized using a
higher over-the-air data rate. Buffering the
data and transmitting in bursts at high data
rate (e.g. 500 kbps) will reduce the time in
active mode, and hence also reduce the
average current consumption significantly.
Reducing the time in active mode will reduce
the likelihood of collisions with other 2.4 GHz
systems, e.g. WLAN.
26.5 Continuous Transmissions
In data streaming applications the CC2550
opens up for continuous transmissions at 500
kbps effective data rate. As the modulation is
done with an I/Q up-converter with LO I/Qsignals coming from a closed loop PLL, there
is no limitation in the length of a transmission.
(Open loop modulation used in some
transceivers often prevents this kind of
continuous data streaming and reduces the
effective data rate.)
26.6 Spectrum Efficient Modulation
CC2500 also has the possibility to use
Gaussian shaped FSK (GFSK). This
spectrum-shaping feature improves adjacent
channel
power
(ACP)
and
occupied
bandwidth. In ‘true’ FSK systems with abrupt
frequency shifting, the spectrum is inherently
broad. By making the frequency shift ‘softer’,
the spectrum can be made significantly
narrower. Thus, higher data rates can be
transmitted in the same bandwidth using
GFSK.
Digital modulation systems under FCC part
15.247 includes FSK and GFSK modulation.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 33 of 54
CC2550
26.7 Low Cost Systems
26.8 Battery Operated Systems
As the CC2550 provides 500 kbps multichannel performance without any external
filters, a very low cost system can be made.
In low power applications, the SLEEP state
should be used when the CC2550 is not active.
A differential antenna will eliminate the need
for a balun, and the DC biasing can be
achieved in the antenna topology, see Figure
3.
26.9 Increasing Output Power
A HC-49 type SMD crystal is used in the
CC2550EM reference design. Note that the
crystal package strongly influences the price.
In a size constrained PCB design a smaller,
but more expensive, crystal may be used.
In some applications it may be necessary to
extend the link range by adding an external
power amplifier.
The power amplifier should be inserted
between the antenna and the balun as shown
in Figure 20.
Figure 20. Block diagram of CC2550 usage with external power amplifier
27
Configuration Registers
The configuration of CC2550 is done by
programming 8-bit registers. The configuration
data based on selected system parameters
are most easily found by using the SmartRF®
Studio software. Complete descriptions of the
registers are given in the following tables. After
chip reset, all the registers have default values
as shown in the tables.
There are 9 Command Strobe Registers, listed
in Table 23. Accessing these registers will
initiate the change of an internal state or
mode. There are 29 normal 8-bit Configuration
Registers, listed in Table 24. Many of these
registers are for test purposes only, and need
not be written for normal operation of CC2550.
There are also 6 Status registers, which are
listed in Table 25. These registers, which are
read-only, contain information about the status
of CC2550.
The TX FIFO is accessed through one 8-bit
register. Only write operations are allowed to
the TX FIFO.
During the address transfer and while writing
to a register or the TX FIFO, a status byte is
returned. This status byte is described in Table
15 on page 15.
Table 26 summarizes the SPI address space.
Registers that are only defined on the CC2500
transceiver are also listed. CC2500 and CC2550
are register compatible, but registers and fields
only implemented in the transceiver always
contain 0 in CC2550.
The address to use is given by adding the
base address to the left and the burst and
read/write bits on the top. Note that the burst
bit has different meaning for base addresses
above and below 0x2F.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 34 of 54
CC2550
Address
Strobe Name
Description
0x30
SRES
Reset chip.
0x31
SFSTXON
0x32
SXOFF
0x33
SCAL
0x35
STX
0x36
SIDLE
Exit TX and turn off frequency synthesizer.
0x39
SPWD
Enter power down mode when CSn goes high.
0x3B
SFTX
Flush the TX FIFO buffer.
0x3D
SNOP
No operation. May be used to pad strobe commands to two bytes for simpler software.
Enable and calibrate frequency synthesizer (if MCSM0.FS_AUTOCAL=1).
Turn off crystal oscillator.
Calibrate frequency synthesizer and turn it off (enables quick start). SCAL can be strobed
in IDLE state without setting manual calibration mode (MCSM0.FS_AUTOCAL=0).
Enable TX. Perform calibration first if MCSM0.FS_AUTOCAL=1.
Table 23: Command strobes
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 35 of 54
CC2550
Address
Register
Description
Details on page number
0x01
IOCFG1
GDO1 output pin configuration
38
0x02
IOCFG0
GDO0 output pin configuration
38
0x03
FIFOTHR
FIFO threshold
38
0x04
SYNC1
Sync word, high byte
39
0x05
SYNC0
Sync word, low byte
39
0x06
PKTLEN
Packet length
39
0x08
PKTCTRL0
Packet automation control
39
0x0A
CHANNR
Channel number
40
0x0D
FREQ2
Frequency control word, high byte
40
0x0E
FREQ1
Frequency control word, middle byte
40
0x0F
FREQ0
Frequency control word, low byte
40
0x10
MDMCFG4
Modulator configuration
40
0x11
MDMCFG3
Modulator configuration
41
0x12
MDMCFG2
Modulator configuration
41
0x13
MDMCFG1
Modulator configuration
42
0x14
MDMCFG0
Modulator configuration
42
0x15
DEVIATN
Modulator deviation setting
43
0x17
MCSM1
Main Radio Control State Machine configuration
43
0x18
MCSM0
Main Radio Control State Machine configuration
44
0x22
FREND0
Front end TX configuration
44
0x23
FSCAL3
Frequency synthesizer calibration
45
0x24
FSCAL2
Frequency synthesizer calibration
45
0x25
FSCAL1
Frequency synthesizer calibration
45
0x26
FSCAL0
Frequency synthesizer calibration
45
0x29
FSTEST
Frequency synthesizer calibration control
45
0x2A
PTEST
Production test
46
0x2C
TEST2
Various test settings
46
0x2D
TEST1
Various test settings
46
0x2E
TEST0
Various test settings
46
Table 24: Configuration registers overview
Address
Register
Description
Details on page number
0x30 (0xF0)
PARTNUM
CC2550 part number
46
0x31 (0xF1)
VERSION
Current version number
46
0x35 (0xF5)
MARCSTATE
Control state machine state
47
0x38 (0xF8)
PKTSTATUS
Current GDOx status and packet status
47
0x39 (0xF9)
VCO_VC_DAC
Current setting from PLL calibration module
48
0x3A (0xFA)
TXBYTES
Underflow and number of bytes in the TX FIFO
48
Table 25: Status registers overview
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 36 of 54
CC2550
SRES
SFSTXON
SXOFF
SCAL
SRX
STX
SIDLE
SAFC
SWOR
SPWD
SFRX
SFTX
SWORRST
SNOP
PATABLE
TX FIFO
PATABLE
TX FIFO
SRES
SFSTXON
SXOFF
SCAL
SRX
STX
SIDLE
SAFC
SWOR
SPWD
SFRX
SFTX
SWORRST
SNOP
PATABLE
RX FIFO
PARTNUM
VERSION
FREQEST
LQI
RSSI
MARCSTATE
WORTIME1
WORTIME0
PKTSTATUS
VCO_VC_DAC
TXBYTES
RXBYTES
PATABLE
RX FIFO
R/W configuration registers, burst access possible
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
0x17
0x18
0x19
0x1A
0x1B
0x1C
0x1D
0x1E
0x1F
0x20
0x21
0x22
0x23
0x24
0x25
0x26
0x27
0x28
0x29
0x2A
0x2B
0x2C
0x2D
0x2E
0x2F
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x39
0x3A
0x3B
0x3C
0x3D
0x3E
0x3F
Read
Single byte
Burst
+0x80
+0xC0
IOCFG2
IOCFG1
IOCFG0
FIFOTHR
SYNC1
SYNC0
PKTLEN
PKTCTRL1
PKTCTRL0
ADDR
CHANNR
FSCTRL1
FSCTRL0
FREQ2
FREQ1
FREQ0
MDMCFG4
MDMCFG3
MDMCFG2
MDMCFG1
MDMCFG0
DEVIATN
MCSM2
MCSM1
MCSM0
FOCCFG
BSCFG
AGCCTRL2
AGCCTRL1
AGCCTRL0
WOREVT1
WOREVT0
WORCTRL
FREND1
FREND0
FSCAL3
FSCAL2
FSCAL1
FSCAL0
RCCTRL1
RCCTRL0
FSTEST
PTEST
AGCTEST
TEST2
TEST1
TEST0
Burst
+0x40
Command Strobes, Status registers
(read only) and multi byte registers
Write
Single byte
+0x00
Table 26: SPI address space (greyed text: for reference only; not implemented on CC2550 )
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 37 of 54
CC2550
27.1 Configuration Register Details
0x01: IOCFG1 – GDO1 output pin configuration
Bit
Field Name
Reset
R/W
Description
7
GDO_DS
0
R/W
Set high (1) or low (0) output drive strength on the
GDO pins.
6
GDO1_INV
0
R/W
Invert output, i.e. select active low / high
5:0
GDO1_CFG[5:0]
46 (0x2E)
R/W
Default is 3-state (see Table 22 on page 31)
0x02: IOCFG0 – GDO0 output pin configuration
Bit
Field Name
Reset
R/W
Description
7
TEMP_SENSOR_ENABLE
0
R/W
Enable analog temperature sensor. Write 0 in all
other register bits when using temperature sensor.
6
GDO0_INV
0
R/W
Invert output, i.e. select active low / high
5:0
GDO0_CFG[5:0]
63 (0x3F)
R/W
Default is CLK_XOSC/192 (see Table 22 on page
31)
0x03: FIFOTHR – FIFO threshold
Bit
Field Name
Reset
R/W
Description
7:4
Reserved
0 (0000)
R/W
Write 0 (0000) for compatibility with possible future
extensions.
3:0
FIFO_THR[3:0]
7 (0111)
R/W
Set the threshold for the TX FIFO. The threshold is
exceeded when the number of bytes in the FIFO is equal to
or higher than the threshold value.
Setting
Bytes in TX FIFO
0 (0000)
61
1 (0001)
57
2 (0010)
53
3 (0011)
49
4 (0100)
45
5 (0101)
41
6 (0110)
37
7 (0111)
33
8 (1000)
29
9 (1001)
25
10 (1010)
21
11 (1011)
17
12 (1100)
13
13 (1101)
9
14 (1110)
5
15 (1111)
1
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 38 of 54
CC2550
0x04: SYNC1– Sync word, high byte
Bit
Field Name
Reset
R/W
Description
7:0
SYNC[15:8]
211 (0xD3)
R/W
8 MSB of 16-bit sync word
0x05: SYNC0 – Sync word, low byte
Bit
Field Name
Reset
R/W
Description
7:0
SYNC[7:0]
145 (0x91)
R/W
8 LSB of 16-bit sync word
0x06: PKTLEN – Packet length
Bit
Field Name
Reset
R/W
Description
7:0
PACKET_LENGTH
255 (0xFF)
R/W
Indicates the packet length when fixed length
packets are enabled.
0x08: PKTCTRL0 – Packet automation control
Bit
Field Name
7
Reserved
6
WHITE_DATA
Reset
R/W
Description
R0
1
R/W
Turn data whitening on / off
0: Whitening off
1: Whitening on
Data whitening can only be used when
PKTCTRL0.CC2400_EN = 0 (default).
5:4
3
PKT_FORMAT[1:0]
CC2400_EN
0 (00)
0
R/W
R/W
Format of RX and TX data
Setting
Packet format
0 (00)
Normal mode, use TX FIFO
1 (01)
Serial Synchronous mode, used for backwards
compatibility
2 (10)
Random TX mode; sends random data using PN9
generator. Used for test.
3 (11)
Asynchronous transparent mode. Data in on GDO0
and Data out on either of the GDO pins
Enable CC2400 support. Use same CRC implementation as
CC2400.
PKTCTRL0.WHITE_DATA must be 0 if
PKTCTRL0.CC2400_EN = 1.
2
CRC_EN
1
R/W
1: CRC calculation enabled
0: CRC disabled
1:0
LENGTH_CONFIG[1:0]
1 (01)
R/W
Configure the packet length
Setting
Packet length configuration
0 (00)
Fixed length packets, length configured in
PKTLEN register
1 (01)
Variable length packets, packet length configured
by the first byte after sync word
2 (10)
Enable infinite length packets
3 (11)
Reserved
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 39 of 54
CC2550
0x0A: CHANNR – Channel number
Bit
Field Name
Reset
R/W
Description
7:0
CHAN[7:0]
0 (0x00)
R/W
The 8-bit unsigned channel number, which is multiplied by
the channel spacing setting and added to the base
frequency.
0x0D: FREQ2 – Frequency control word, high byte
Bit
Field Name
Reset
R/W
Description
7:6
FREQ[23:22]
1 (01)
R
FREQ[23:22] is always binary 01 (the FREQ2 register is in the range
85 to 95 with 26 - 27 MHz crystal)
5:0
FREQ[21:16]
30
(0x1E)
R/W
FREQ[23:0] is the base frequency for the frequency synthesiser in
16
increments of FXOSC/2 .
f carrier =
f XOSC
⋅ FREQ [23 : 0]
216
The default frequency word gives a base frequency of 2464 MHz,
assuming a 26.0 MHz crystal. With the default channel spacing
settings, the following FREQ2 values and channel numbers can be
used:
FREQ2
Base frequency
Frequency range (CHAN
numbers)
91 (0x5B)
2386 MHz
2400.2-2437 MHz (71-255)
92 (0x5C)
2412 MHz
2412-2463 MHz (0-255)
93 (0x5D)
2438 MHz
2431-2483.4 MHz (0-227)
94 (0x5E)
2464 MHz
2464-2483.4 MHz (0-97)
0x0E: FREQ1 – Frequency control word, middle byte
Bit
Field Name
Reset
R/W
Description
7:0
FREQ[15:8]
196 (0xC4)
R/W
Ref. FREQ2 register
0x0F: FREQ0 – Frequency control word, low byte
Bit
Field Name
Reset
R/W
Description
7:0
FREQ[7:0]
236 (0xEC)
R/W
Ref. FREQ2 register
0x10: MDMCFG4 – Modulator configuration
Bit
Field Name
7:4
Reserved
3:0
DRATE_E[3:0]
Reset
12 (1100)
R/W
Description
R0
Defined on the transceiver version
R/W
The exponent of the user specified symbol rate
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 40 of 54
CC2550
0x11: MDMCFG3 – Modulator configuration
Bit
Field Name
Reset
R/W
Description
7:0
DRATE_M[7:0]
34 (0x22)
R/W
The mantissa of the user specified symbol rate. The symbol
rate is configured using an unsigned, floating-point number
th
with 9-bit mantissa and 4-bit exponent. The 9 bit is a
hidden ‘1’. The resulting data rate is:
RDATA =
(256 + DRATE _ M ) ⋅ 2 DRATE _ E ⋅ f
2 28
XOSC
The default values give a data rate of 115.051 kbps (closest
setting to 115.2 kbps), assuming a 26.0 MHz crystal.
0x12: MDMCFG2 – Modulator configuration
Bit
Field Name
7
Reserved
6:4
MOD_FORMAT[2:0]
Reset
R/W
Description
R0
1 (001)
R/W
The modulation format of the radio signal
Setting
3
MANCHESTER_EN
0
R/W
Modulation format
0 (000)
FSK
1 (001)
GFSK
2 (010)
-
3 (011)
OOK
4 (100)
-
5 (101)
-
6 (110)
-
7 (111)
MSK
Enables Manchester encoding/decoding
0 = Disable
1 = Enable
2:0
SYNC_MODE[2:0]
2 (010)
R/W
Combined sync-word qualifier mode.
The values 0 (000) and 4 (100) disables preamble
and sync word transmission. The values 1 (001), 2
(001), 5 (101) and 6 (110) enables 16-bit sync word
transmission. The values 3 (011) and 7 (111)
enables repeated sync word transmission. The table
below lists the meaning of each mode (for
compatibility with the CC2500 transceiver):
Setting
Sync-word qualifier mode
0 (000)
No preamble/sync word
1 (001)
15/16 sync word bits detected
2 (010)
16/16 sync word bits detected
3 (011)
30/32 sync word bits detected
4 (100)
No preamble/sync, carrier-sense
above threshold
5 (101)
15/16 + carrier-sense above threshold
6 (110)
16/16 + carrier-sense above threshold
7 (111)
30/32 + carrier-sense above threshold
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 41 of 54
CC2550
0x13: MDMCFG1 – Modulator configuration
Bit
Field Name
Reset
R/W
Description
7
FEC_EN
0
R/W
Enable Forward Error Correction (FEC) with interleaving for
packet payload
0 = Disable
1 = Enable
6:4
NUM_PREAMBLE[2:0]
3:2
Reserved
1:0
CHANSPC_E[1:0]
2 (010)
R/W
Sets the minimum number of preamble bytes to be
transmitted
Setting
Number of preamble bytes
0 (000)
2
1 (001)
3
2 (010)
4
3 (011)
6
4 (100)
8
5 (101)
12
6 (110)
16
7 (111)
24
R0
2 (10)
R/W
2 bit exponent of channel spacing
0x14: MDMCFG0 – Modulator configuration
Bit
Field Name
Reset
R/W
Description
7:0
CHANSPC_M[7:0]
248 (0xF8)
R/W
8-bit mantissa of channel spacing (initial 1 assumed). The
channel spacing is multiplied by the channel number CHAN and
added to the base frequency. It is unsigned and has the format:
∆f CHANNEL =
f XOSC
⋅ (256 + CHANSPC _ M ) ⋅ 2 CHANSPC _ E ⋅ CHAN
218
The default values give 199.951 kHz channel spacing (the
closest setting to 200 kHz), assuming 26.0 MHz crystal
frequency.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 42 of 54
CC2550
0x15: DEVIATN – Modulator deviation setting
Bit
Field Name
7
Reserved
6:4
DEVIATION_E[2:0]
3
Reserved
2:0
DEVIATION_M[2:0]
Reset
R/W
Description
R0
4 (100)
R/W
Deviation exponent
R0
7 (111)
R/W
When MSK modulation is enabled:
Sets fraction of symbol period used for phase change.
When FSK modulation is enabled:
Deviation mantissa, interpreted as a 4-bit value with MSB
implicit 1. The resulting FSK deviation is given by:
f dev =
f xosc
⋅ (8 + DEVIATION _ M ) ⋅ 2 DEVIATION _ E
17
2
The default values give ±47.607 kHz deviation, assuming
26.0 MHz crystal frequency.
0x17: MCSM1 – Main Radio Control State Machine configuration
Bit
Field Name
Reset
7:6
Reserved
R0
5:2
Reserved
R0
Defined on the transceiver version
1:0
TXOFF_MODE[1:0]
R/W
Select what should happen when a packet has been sent
(TX)
0 (00)
R/W
Description
Setting
Next state after finishing packet transmission
0 (00)
IDLE
1 (01)
FSTXON
2 (10)
Stay in TX (start sending preamble)
3 (11)
Do not use, not implemented on CC2550
(Go to RX)
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 43 of 54
CC2550
0x18: MCSM0 – Main Radio Control State Machine configuration
Bit
Field Name
7:6
Reserved
5:4
FS_AUTOCAL[1:0]
3:2
PO_TIMEOUT
Reset
R/W
Description
R0
0 (00)
2 (10)
R/W
R/W
Automatically calibrate when going to TX or back to IDLE
Setting
When to perform automatic calibration
0 (00)
Never (manually calibrate using SCAL strobe)
1 (01)
When going from IDLE to TX (or FSTXON)
2 (10)
When going from TX back to IDLE
3 (11)
Every 4 time when going from TX to IDLE
th
Programs the number of times the six-bit ripple counter must expire
after XOSC has stabilized before CHP_RDYn goes low.
The XOSC is off during power-down so the regulated digital supply
voltage has time to stabilize while waiting for the crystal to be stable
even with PO_TIMEOUT to 0.
Setting
Expire count
Timeout after XOSC start
0 (00)
1
Approx. 2.3 – 2.4 µs
1 (01)
16
Approx. 37 – 39 µs
2 (10)
64
Approx. 149 – 155 µs
3 (11)
256
Approx. 597 – 620 µs
Exact timeout depends on crystal frequency.
In order to reduce start up time from the SLEEP state, this field is
preserved in powerdown (SLEEP state).
1:0
Reserved
R0
Defined on the transceiver version
0x22: FREND0 – Front end TX configuration
Bit
Field Name
Reset
7:6
Reserved
5:4
LODIV_BUF_CURRENT_TX[1:0]
3
Reserved
2:0
PA_POWER[2:0]
R/W
Description
R0
1 (01)
R/W
Adjusts current TX LO buffer (input to PA). The
value to use in this field is given by the SmartRF®
Studio software.
R0
0 (000)
R/W
Selects PA power setting. This value is an index to
the PATABLE, which can be programmed with up to
8 different PA settings. The PATABLE settings from
index ‘0’ to the PA_POWER value are used for
power ramp-up/ramp-down at the start/end of
transmission in all TX modulation formats.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 44 of 54
CC2550
0x23: FSCAL3 – Frequency synthesizer calibration
Bit
Field Name
Reset
R/W
Description
7:6
FSCAL3[7:6]
2 (10)
R/W
Frequency synthesizer calibration configuration. The value to write
in this register before calibration is given by the SmartRF® Studio
software.
5:4
CHP_CURR_CAL_EN[1:0]
2 (10)
R/W
Disable charge pump calibration stage when 0
3:0
FSCAL3[3:0]
9
(1001)
R/W
Frequency synthesizer calibration result register.
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
0x24: FSCAL2 – Frequency synthesizer calibration
Bit
Field Name
7:6
Reserved
5:0
FSCAL2[5:0]
Reset
R/W
Description
R0
10
(0x0A)
R/W
Frequency synthesizer calibration result register.
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
0x25: FSCAL1 – Frequency synthesizer calibration
Bit
Field Name
7:6
Reserved
5:0
FSCAL1[5:0]
Reset
R/W
Description
R0
32
(0x20)
R/W
Frequency synthesizer calibration result register.
Fast frequency hopping without calibration for each hop can be
done by calibrating upfront for each frequency and saving the
resulting FSCAL3, FSCAL2 and FSCAL1 register values. Between
each frequency hop, calibration can be replaced by writing the
FSCAL3, FSCAL2 and FSCAL1 register values corresponding to
the next RF frequency.
0x26: FSCAL0 – Frequency synthesizer calibration
Bit
Field Name
Reset
R/W
Description
7
Reserved
6:5
Reserved
0 (00)
R0
Defined on the transceiver version
4:0
FSCAL0[4:0]
13
(0x0D)
R/W
Frequency synthesizer calibration control. The value to use in
register field is given by the SmartRF® Studio software.
R0
0x29: FSTEST – Frequency synthesizer calibration control
Bit
Field Name
Reset
R/W
Description
7:0
FSTEST[7:0]
87
(0x57)
R/W
For test only. Do not write to this register.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 45 of 54
CC2550
0x2A: PTEST – Production test
Bit
Field Name
Reset
R/W
Description
7
PTEST[7:0]
127
(0x7F)
R/W
Writing 0xBF to this register makes the on-chip temperature sensor
available in the IDLE state. The default 0x7F value should then be
written back before leaving the IDLE state.
Other use of this register is for test only.
0x2C: TEST2 – Various test settings
Bit
Field Name
Reset
R/W
Description
7:0
TEST2[7:0]
152
(0x98)
R/W
The value to use in this register is given by the SmartRF® Studio
software.
0x2D: TEST1 – Various test settings
Bit
Field Name
Reset
R/W
Description
7:0
TEST1[7:0]
49 (0x31)
R/W
The value to use in this register is given by the SmartRF®
Studio software.
0x2E: TEST0 – Various test settings
Bit
Field Name
Reset
R/W
Description
7:0
TEST0[7:0]
11 (0x0B)
R/W
The value to use in this register is given by the SmartRF®
Studio software.
27.2 Status register details
0x30 (0xF0): PARTNUM – Chip ID
Bit
Field Name
Reset
R/W
Description
7:0
PARTNUM[7:0]
130 (0x82)
R
Chip part number
0x31 (0xF1): VERSION – Chip ID
Bit
Field Name
Reset
R/W
Description
7:0
VERSION[7:0]
2 (0x02)
R
Chip version number.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 46 of 54
CC2550
0x35 (0xF5): MARCSTATE – Main Radio Control State Machine state
Bit
Field Name
Reset
R/W
7:5
Reserved
R0
4:0
MARC_STATE[4:0]
R
Description
Main Radio Control FSM State
Value
State name
State (Figure 13, page 23)
0 (0x00)
SLEEP
SLEEP
1 (0x01)
IDLE
IDLE
2 (0x02)
XOFF
XOFF
3 (0x03)
VCOON_MC
MANCAL
4 (0x04)
REGON_MC
MANCAL
5 (0x05)
MANCAL
MANCAL
6 (0x06)
VCOON
FS_WAKEUP
7 (0x07)
REGON
FS_WAKEUP
8 (0x08)
STARTCAL
CALIBRATE
9 (0x09)
BWBOOST
SETTLING
10 (0x0A)
FS_LOCK
SETTLING
11 (0x0B)
IFADCON
SETTLING
12 (0x0C)
ENDCAL
CALIBRATE
13 (0x0D)
NA
NA
14 (0x0E)
NA
NA
15 (0x0F)
NA
NA
16 (0x10)
NA
NA
17 (0x11)
NA
NA
18 (0x12)
FSTXON
FSTXON
19 (0x13)
TX
TX
20 (0x14)
TX_END
TX
21 (0x15)
NA
NA
22 (0x16)
TX_UNDERFLOW
TX_UNDERFLOW
0x38 (0xF8): PKTSTATUS – Current GDOx status
Bit
Field Name
7:2
Reset
R/W
Description
Reserved
R0
Defined on the transceiver version
1
Reserved
R0
0
GDO0
R
Current GDO0 value. Note: the reading gives the noninverted value irrespective what IOCFG0.GDO0_INV is
programmed to.
It is not recommended to check for PLL lock by reading
PKTSTATUS[0] with GDO0_CFG = 0x0A.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 47 of 54
CC2550
0x39 (0xF9): VCO_VC_DAC – Current setting from PLL calibration module
Bit
Field Name
Reset
7:0
VCO_VC_DAC[7:0]
R/W
Description
R
Status register for test only.
0x3A (0xFA): TXBYTES – Underflow and number of bytes
Bit
Field Name
Reset
R/W
7
TXFIFO_UNDERFLOW
R
6:0
NUM_TXBYTES
R
Description
Number of bytes in TX FIFO
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 48 of 54
CC2550
28
Package Description (QLP 16)
All dimensions are in millimetres, angles in degrees. NOTE: The CC2550 is available in RoHS
lead-free package only.
Figure 21: Package dimensions drawing (the actual package has 16 pins)
Package
type
QLP 16 (4x4)
A
A1
A2
D
D1
Min
0.75
0.005
0.55
3.90
3.65
Typ.
0.85
0.025
0.65
4.00
3.75
Max
0.95
0.045
0.75
4.10
3.85
D2
E
E1
3.90
3.65
2.30
4.00
3.75
4.10
3.85
E2
2.30
L
T
b
0.45
0.190
0.23
0.55
0.65
0.28
0.245
e
0.65
0.35
Table 27: Package dimensions
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 49 of 54
CC2550
28.1 Recommended PCB layout for package (QLP 16)
Figure 22: Recommended PCB layout for QLP 16 package
Note: The figure is an illustration only and not to scale. There are five 10 mil diameter via holes
distributed symmetrically in the ground pad under the package. See also the CC2550EM
reference design.
28.2 Package thermal properties
Thermal resistance
Air velocity [m/s]
Rth,j-a [K/W]
0
40.1
Table 28: Thermal properties of QLP 16 package
28.3 Soldering information
The recommendations for lead-free reflow in IPC/JEDEC J-STD-020C should be followed.
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 50 of 54
CC2550
28.4 Tray specification
CC2550 can be delivered in standard QLP 4x4 mm shipping trays.
Tray Specification
Package
Tray Width
Tray Height
Tray Length
Units per Tray
QLP 16
125.9 mm
7.62 mm
322.6 mm
490
Table 29: Tray specification
28.5 Carrier tape and reel specification
Carrier tape and reel is in accordance with EIA Specification 481.
Tape and Reel Specification
Package
Tape Width
Component
Pitch
Hole
Pitch
Reel
Diameter
Units per Reel
QLP 16
12 mm
8 mm
4 mm
13 inches
2500
Table 30: Carrier tape and reel specification
29
Ordering Information
Chipcon Part
Number
TI Part Number
Description
Minimum Order Quantity
(MOQ)
CC2550-RTY1
CC2550RTK
CC2550 QLP16 RoHS Pb-free 490/tray
490 (tray)
CC2550-RTR1
CC2550RTKR
CC2550 QLP16 RoHS Pb-free 2500/T&R
2500 (tape and reel)
CC2500-CC2550DK
CC2500-CC2550DK
CC2500_CC2550 Development Kit
1
CC2550EMK
CC2550EMK
CC2500 Evaluation Module Kit
1
Table 31: Ordering information
30
General Information
30.1 Document History
Revision
Date
Description/Changes
1.2
2006-06-28
Added figures to table on SPI interface timing requirements.
Added information about SPI read.
Updates to text and included new figure in section on arbitrary length configuration.
Added information that RF frequencies at n/2·crystal frequency (n is an integer number)
should not be used due to spurious signals at these frequencies .
Updates to text and included new figures in section on power-on start-up sequence.
Added information about how to check for PLL lock in section on VCO.
Better explanation of some of the signals in table of GDO signal selection.
Added section on wideband modulation not using spread spectrum under section on
system considerations and guidelines.
Added more detailed information on PO_TIMEOUT in register MCSM0.
Changes to ordering information.
1.1
2005-06-27
Updated TEST1 register default value. 26-27 MHz crystal range. Added matching
information. Added information about using a reference signal instead of a crystal.
1.0
2005-01-24
First preliminary data sheet release.
Table 32: Document history
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 51 of 54
CC2550
30.2 Product Status Definitions
Data Sheet Identification
Product Status
Definition
Advance Information
Planned or Under
Development
This data sheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
Preliminary
Engineering Samples
and Pre-Production
Prototypes
This data sheet contains preliminary data, and
supplementary data will be published at a later date.
Chipcon reserves the right to make changes at any
time without notice in order to improve design and
supply the best possible product. The product is not
yet fully qualified at this point.
No Identification Noted
Full Production
This data sheet contains the final specifications.
Chipcon reserves the right to make changes at any
time without notice in order to improve design and
supply the best possible product.
Obsolete
Not In Production
This data sheet contains specifications on a product
that has been discontinued by Chipcon. The data
sheet is printed for reference information only.
Table 33: Product status definitions
PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 52 of 54
CC2550
31
Address Information
Texas Instruments Norway AS
Gaustadalléen 21
N-0349 Oslo
NORWAY
Tel: +47 22 95 85 44
Fax: +47 22 95 85 46
Web site: http://www.ti.com/lpw
32
TI Worldwide Technical Support
Internet
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PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 53 of 54
CC2550
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Phone
Fax
Email
Internet
International
Domestic
Australia
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Hong Kong
India
Indonesia
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PRELIMINARY Data Sheet (Rev.1.2)
SWRS039A
Page 54 of 54
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