Texas Instruments CC2431 Datasheet

CC2431
System-on-Chip for 2.4 GHz ZigBee
Applications
ZigBeesystems
2.4 GHz IEEE 802.15.4 systems
Home/building automation
Industrial Control and Monitoring
Low power wireless sensor networks
Access Control
Product Description
The
CC2431
for wireless sensor networking ZigBee™ /
802.15.4 solutions with location detection engine hardware onboard allowing location accuracy of around 3 meters or less. It enables ZigBee™ nodes to be built with very low total bill-of-material costs. The combines the excellent performance of the leading industry-standard enhanced 8051 MCU, 128 KB flash memory, 8 KB RAM and many other powerful features. Combined with the industry leading ZigBee™ protocol stack (Z-Stack™) from Figure 8 Wireless / Chipcon, the provides the market’s most competitive ZigBee™ solution.
is a true System-On-Chip (SOC)
CC2431
CC2420
RF transceiver with an
CC2431
IEEE 802.15.4 with Location Engine
PC peripherals
Set-top boxes and remote controls
Consumer Electronics
Container/Vehicle Tracking
Active RFID
Inventory Control
CC2431
The ultra low power consumption is required. This is achieved by various operating modes. Short transition times between these modes further ensure low power consumption.
is highly suited for systems where
Key Features
Location Engine accurately calculates the location of a node in a network
High performance and low power 8051 microcontroller core.
2.4 GHz IEEE 802.15.4 compliant RF transceiver (industry leading radio core).
Excellent receiver sensitivity and robustness to interferers
128 KB in-system programmable flash
8 KB RAM, 4 KB with data retention in
all power modes
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 at this point is not fully qualified.
CC2431 PRELIMINARY Data Sheet (Rev. 1.01) SWRS034A Page 1 of 13
CC2420
Powerful DMA functionality
Very few external components
Only a single crystal needed for mesh
network systems
Low current consumption (RX: 27mA, TX: 25mA, microcontroller running at 32 MHz)
Only 0.9µA current consumption in
power-down mode, where external interrupts or the RTC can wake up the system
Key Features (continued)
Less than 0.6µA current consumption in power-down mode, where external interrupts can wake up the system
Very fast transition times from low­power modes to active mode enables ultra low average power consumption in low duty-cycle systems
CSMA/CA hardware support
Wide supply voltage range (2.0V –
3.6V)
Digital RSSI/ LQI support
Battery monitor and temperature
sensor
8-14 bits ADC with up to eight inputs
CC2431
128-bit AES security coprocessor
Two powerful USARTs with support
for several serial protocols.
Hardware debug support
Watchdog timer
One IEEE 802.15.4 MAC Timer, one
general 16-bit timer and two 8-bit timers
RoHS compliant 7x7mm QLP48 package
21 general I/O pins, two with 20mA sink/source capability
Powerful and flexible development
tools available
Note:
The CC2431 and the CC2430 are pin compatible, and the MCU and RF parts of the CC2430-F128 are identical to the CC2431 except the Location Engine. This data sheet complements the CC2430 data sheet with a description of the Location Engine. For complete information about the CC2431, please refer to the CC2430 data sheet in addition to this data sheet.
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A
Page 2 of 13
CC2431
Table Of Contents
1 REGISTER CONVENTIONS ................................................................................................................. 4
2 LOCATION ENGINE .............................................................................................................................. 5
2.1 LOCATION ENGINE OPERATION ................................................................................................................... 5
2.2 LOCATION ENGINE REGISTERS .................................................................................................................. 10
3 ORDERING INFORMATION .............................................................................................................. 12
4 GENERAL INFORMATION ................................................................................................................ 12
4.1 DOCUMENT HISTORY................................................................................................................................. 12
4.2 PRODUCT STATUS DEFINITIONS ................................................................................................................. 12
4.3 DISCLAIMER .............................................................................................................................................. 13
4.4 TRADEMARKS ............................................................................................................................................ 13
4.5 LIFE SUPPORT POLICY ............................................................................................................................... 13
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 3 of 13
CC2431
1 Register conventions
Each RF register is described in a separate table. The table heading is given in the following format:
REGISTER NAME (XDATA Address)
In the register descriptions, each register bit is shown with a symbol indicating the access mode of the register bit. The register values are always given in binary notation unless prefixed by ‘0x’ which indicates hexadecimal notation.
Symbol Access Mode
R/W Read/write
R Read only
R0 Read as 0
R1 Read as 1
W Write only
W0 Write as 0
W1 Write as 1
H0 Hardware clear
H1 Hardware set
Table 1: Register bit conventions
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 4 of 13
2 Location Engine
The Location Engine is used to estimate the position of nodes in an ad-hoc wireless network. Reference nodes exist with known coordinates, typically because they are part of an installed infrastructure. Other nodes are blind nodes, whose coordinates need to be estimated. These blind nodes are often mobile and attached to assets that need to be tracked.
The Location Engine implements a distributed computation algorithm that uses received signal strength indicator (RSSI) values from known reference nodes, such as mobile neighbor nodes with the same Location Engine, or fixed infrastructure nodes. Performing location calculations at the node level reduces network traffic and communication delays otherwise present in a centralized computation approach.
The Location Engine has the following main features:
Three to eight reference nodes can be used for the location estimation algorithm
Location estimate with resolution of 0.5 meters
Time to estimate node location less than 40 µs
Location range 64 x 64 meters
Location error can be less than 3
meters, depending on factors described below
CC2431
To achieve the best possible accuracy one should use antennas that have near­isotropic radiation characteristics. The location error depends on signal environment, deployment pattern of reference nodes and the density of reference nodes in a given area. In general, having more reference nodes available improves the accuracy of the location estimation.
2.1 Location Engine Operation
This section describes the basic steps required to obtain location estimates from the Location Engine.
The Location Engine requires a set of three to eight reference coordinates to be input together with a set of measured parameters. The output from the Location Engine consists of a pair of estimated location coordinates.
Before any input data is written, the Location Engine must be enabled by writing a 1 to the enable bit, When the Location Engine is not in use, writing a 0 to power consumption of the CC2431 by gating off the Engine’s clock signal.
Figure 1 shows the basic operation of the Location Engine.
LOCENG.EN will reduce the
LOCENG.EN.
Runs location estimation with minimum CPU usage
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 5 of 13
CC2431
LOCENG.EN=1
Load
coordinate
pairs?
yes
LOCENG.REFLD=1
no
Load reference
coordinate pairs
Loaded 8
coordinate
pairs?
yes
LOCENG.REFLD=0 LOCENG.PARLD=1
Load measured
parameter or zero for
unused reference
Loaded 10
parameters?
yes
LOCENG.PARLD=0
LOCENG.RUN=1
no
no
Wait
LOCENG.DONE=1
?
yes
Read LOCX, LOCY
and LOCMIN
LOCENG.EN=0
no
Figure 1: Location Engine Operation
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 6 of 13
CC2431
2.1.1 Reference Coordinates
The Location Engine requires a set of between three and eight reference coordinates [x0, y0, x1, y1, … x7, y7] to be input. The reference coordinates express each reference nodes position in meters, as unsigned values in the interval [0,
63.75] meters. The finest possible resolution is 0.25 meter. The format used is fixed-point data with the two LSBs representing the fractional part and the remaining six bits representing the integer part.
Reference coordinates are loaded into the RF register
REFCOORD. Before writing to
REFCOORD, a 1 must be written to the
register bit that a set of reference coordinates are being written. Once the coordinate load process commences ( =1), eight coordinate pairs must always be written. However, it is possible for the Location Engine to use less than eight reference coordinates, by marking certain reference coordinates as unused. Zeros can be used to fill the unused reference coordinate slots, and they will be interpreted as unused when 0.0 is loaded as the RSSI value for those reference coordinates.
The reference coordinates are written in the order [x0, y0, x1, y1, …, x7, y7] to the register have been written, a 0 is written to the register bit
2.1.2 Measured Parameters
After the reference coordinates have been written, a set of measured parameters must be input to the Location Engine. These parameters consist of two radio parameters and eight RSSI values. The radio parameters are the values A and n. These radio parameters are used in the Engine’s algorithm used to find the estimated location. The parameters A and
LOCENG.REFLD to indicate
LOCENG.REFLD
REFCOORD. After all coordinates
LOCENG.REFLD.
n can be adjusted to describe the propagation environment in which a network of devices will operate.
2.1.2.1 Parameter Definitions
The measured parameters are described in this section together with how these should be estimated.
2.1.2.1.1 Parameter A
The radio parameter A is defined as the absolute value of the average power in dBm received at a close-in reference distance of one meter from the transmitter, assuming an omni-directional radiation pattern. For example, if the mean received power at one meter is -40 dBm, the parameter A is specified as 40.
The Engine expects the parameter A to be in the range [30.0, 50.0] with precision 0.5. The parameter A is given as an unsigned fixed-point value where the LSB bit is the fractional bit and the remaining bits are the integer part. A typical value for A is 40.0.
2.1.2.1.2 Parameter n
The radio parameter n is defined as the path loss exponent that describes the rate at which the signal power decays with increasing distance from the transmitter. This decay is proportional to d the distance between transmitter and receiver.
The actual parameter n value written to the Location Engine is an integer index value selected from a lookup table shown in Table 2.
As an example, in the case when the value n=2.98 is found from measurements, the closest available value of n in the lookup table is 3.00, corresponding to index 13. Therefore, the integer value 13 is used for the parameter n written to the Location Engine.
Refer to section 2.1.2.1.3 in order to find the value for n to be used.
-n
where d is
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 7 of 13
x
CC2431
n index n n inde
0 1.000 16 3.375 1 1.250 17 3.500 2 1.500 18 3.625 3 1.750 19 3.750 4 1.875 20 3.875 5 2.000 21 4.000 6 2.125 22 4.125 7 2.250 23 4.250 8 2.375 24 4.375 9 2.500 25 4.500 10 2.625 26 4.625 11 2.750 27 5.000 12 2.875 28 5.500 13 3.000 29 6.000 14 3.125 30 7.000 15 3.250 31 8.000
Table 2: n parameter lookup table
The parameter n is written to the Location Engine as an integer index in the range [0, 31] as the index is given as an integer value with no fractional bits, e.g. the value n = 7 is loaded as 00000111. A typical value for n is 13.
2.1.2.1.3 Parameter Estimation
The parameters A and n can be estimated empirically by collecting RSSI data (and therefore path loss data) for which the distances between the transmitting and receiving devices are known. Figure 2 is a scatter plot of abs(RSSI) data versus log distance in meters. A least-squares best-fit line is used to glean the specific values of
n
A and n for the environment in which the data were measured:
A is the y-intercept of the line, and
n is the slope of the line
The data in Figure 2 give A=42.4 and n=2.98 for that environment. Note that the
plot in this example does not show the actual y-intercept i.e. the point on the line where x=0.
The value of A loaded into the engine in this case would by 42.5. The value of n loaded into the engine, is seen to be 13 from Table 2.
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 8 of 13
CC2431
95
90
85
80
75
70
Path Loss (dB)
65
60
55
50
45
2 4 6 8 10 12 14
Path Loss vs. log-dis tance for sourc e 0x85, Z=2.1082. A= 42.4103, n= 2.9773
10*log10(distance)
Figure 2: Path loss vs. log distance
2.1.2.1.4 RSSI Values
The RSSI values are the RSSI measurements corresponding to the set of reference coordinates. The RSSI values are within the interval [-40 dBm, -95 dBm] with precision 0.5 dBm. The negative sign is removed in the value written. As an example, in the case where the value RSSI = -50.35 dB, this would be written into the location engine as 50.5.
Note that a value of 0.0 must be written as RSSI value for unused reference coordinates. The engine will not function correctly if only some of the parameters are loaded.
2.1.2.2 Loading Parameters
All measured parameters are loaded into the RF register
MEASPARM, a 1 must be written to the
to register bit
MEASPARM. Before writing
LOCENG.PARLD to indicate
that a set of measured parameters are being written. Once the parameter load process commences (
LOCENG.PARLD
=1), all ten parameters must be written.
The measured parameters must be written in the order [A, n, rssi0, rssi1, … rssi7] to
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 9 of 13
MEASPARM register. Once the
the parameter load process commences (
LOCENG.PARLD =1) it must be
completed. Eight RSSI values must be written, so any unused slots must be written as zeros. After all ten parameters have been written, a 0 must be written to the register bit
LOCENG.PARLD.
2.1.3 Location Estimation
The estimated location coordinates are given in meters in the interval [0.0, 63.5] with precision 0.5 m. The data format uses the LSB bit as the fractional part.
When reference coordinates and measured parameters have been loaded, the location estimate is calculated by writing 1 to the
LOCENG.RUN register bit.
The estimated coordinates can be read from the
LOCX and LOCY registers when
LOCENG.DONE is set to 1. This occurs
1200 system clock cycles (16/32 MHz) after
LOCENG.RUN was set to 1. The
Location Engine does not produce any interrupt requests.
The estimated coordinates remain valid in
LOCX and LOCY registers until new
the
CC2431
results have been calculated or until a reset.
Note that operation of the Location Engine.
2.2 Location Engine Registers
This section describes the RF registers associated with the Location Engine. These registers are:
XDATA Address
0xDF55 REFCOORD Reference coordinates input
0xDF56 MEASPARM Measured parameters input
0xDF57 LOCENG Location Engine control and status
0xDF58 LOCX Location estimate X coordinate
0xDF59 LOCY Location estimate Y coordinate
0xDF5A LOCMIN Minimum function estimate
0xDF60 CHVER Chip Version
0xDF61 CHIPID Chip Identification
LOCENG.EN must be 1 during
LOCENG Location Engine
control and status
REFCOORD Reference
coordinates input
MEASPARM Measured
parameters input
Table 3 : Overview of Location Engine RF registers
Register name Description
The RF registers reside in XDATA memory space. Table 3 gives an overview of register addresses while the remaining tables in this section describe each register in detail. Refer also to section 1 for Register conventions.
For the remaining RF registers refer to the CC2430 Data Sheet.
LOCX Location estimate
X coordinate
LOCY Location estimate
Y coordinate
LOCMIN Minimum function
estimate
Bit Name Reset R/W Description
7:0 REFCOORD 0 R/W
Table 4: Register REFCOORD (0xDF55)
Bit Name Reset R/W Description
7:0 MEASPARM 0 R/W
Table 5: Register MEASPARM (0xDF56)
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 10 of 13
Location Engine reference coordinate [x0, y0, x1, y1, … x7, y7]
Location Engine measured parameters of channel and reference nodes [A, n, rssi0, rssi1, …, rssi7]
Bit Name Reset R/W Description
CC2431
7:5 - 00 R0
4 EN 0 R/W
3 DONE 0 R
2 PARLD 0 R/W
1 REFLD 0 R/W
0 RUN 0 R0W1
Reserved, read as 0.
Enable location engine
0 Disable location engine
1 Enable location engine
Estimation completed. After 1 has been written to RUN, this bit is cleared and then set to 1 when the estimated data is ready.
Load parameters. This bit shall be written as 1 before the set of parameters are written to MEASPARM. Write 0 to this bit after the last parameter has been written.
Load reference coordinates. This bit shall be written as 1 before the set of coordinates are written to REFCOORD. Write 0 to this bit after the last coordinate has been written.
Location estimate start. This bit shall be written as 1 when desired coordinates and parameters have been written to REFCOORD and MEASPARM registers. Estimation process starts when 1 is written to this bit. Always read as
0.
Table 6: Register LOCENG (0xDF57)
Bit Name Reset R/W Description
7:0 LOCX 00h R
Location estimate X coordinate.
Table 7: Register LOCX (0xDF58)
Bit Name Reset R/W Description
7:0 LOCY 00h R
Location estimate Y coordinate.
Table 8: Register LOCY (0xDF59)
Bit Name Reset R/W Description
7:0 LOCMIN 00h R
Location estimate minimum value
Table 9: Register LOCMIN (0xDF5A)
Bit Name Reset R/W Description
7:0 VERSION[7:0] 0x01 R
Chip revision number
Table 10: Register CHVER (0xDF60)
Bit Name Reset R/W Description
7:0 CHIPID[7:0] 0x89 R
Chip identification number. Always read as 0x89.
Table 11: Register CHIPID (0xDF61)
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 11 of 13
3 Ordering Information
CC2431
Ordering part number Description Minimum Order
1371 CC2431-RTB1 CC2431, QLP48 package, RoHS compliant Pb-free assembly in
tubes with 43 pcs per tube, Single Chip RF Transceiver
1372 CC2431-RTR1 CC2431, QLP48 package, RoHS compliant Pb-free assembly,
tape and reel with 2500 pcs per reel, Single Chip RF Transceiver
1367 CC2431DK CC2431 ZigBee Development Kit 1
1368 CC2431ZDK Pro CC2431 ZigBee Development Kit including support and training 1
Quantity (MOQ)
43
2500
Table 12: Ordering Information
4 General Information
4.1 Document History
Revision Date Description/Changes
1.0 2005-11-30 First release
1.01 2006-05-11 Preliminary status updated
Table 13: Document History

4.2 Product Status Definitions

Data Sheet Identification Product Status Definition
Advance Information Planned or Under
Development
Preliminary Engineering Samples
and Pre-Production Prototypes
No Identification Noted Full Production This data sheet contains the final specifications. Chipcon
Obsolete Not In Production This data sheet contains specifications on a product that has
This data sheet contains the design specifications for product development. Specifications may change in any manner without notice.
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.
reserves the right to make changes at any time without notice in order to improve design and supply the best possible product.
been discontinued by Chipcon. The data sheet is printed for reference information only.
Table 14: Product Status Definitions
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 12 of 13
CC2431
4.3 Disclaimer
Chipcon AS believes the information contained herein is correct and accurate at the time of this printing. However, Chipcon AS reserves the right to make changes to this product without notice. Chipcon AS does not assume any responsibility for the use of the described product; neither does it convey any license under its patent rights, or the rights of others. The latest updates are available at the Chipcon website or by contacting Chipcon directly.
As far as possible, major changes of product specifications and functionality, will be stated in product specific Errata Notes published at the Chipcon website. Customers are encouraged to sign up for the Chipcon Newsletter for the most recent updates on products and support tools.
When a product is discontinued this will be done according to Chipcon’s procedure for obsolete products as described in Chipcon’s Quality Manual. This includes informing about last-time-buy options. The Quality Manual can be downloaded from Chipcon’s website.
Compliance with regulations is dependent on complete system performance. It is the customer’s responsibility to ensure that the system complies with regulations.
The ZigBee Specification includes intellectual property rights of ZigBee Alliance member/promoter companies. Chipcon is a ZigBee Alliance Promoter. Under the ZigBee Alliance terms of use, no part of the Specification may be used by a company in the development of a product for sale without such company becoming a member of the ZigBee Alliance. Therefore, the Figure 8 Wireless Z-Stack™ may only be used for commercial purposes by ZigBee Alliance member companies. If a customer desires to use the Figure 8 Wireless Z-Stack™ or any other third party ZigBee stack together with a product described in this datasheet, the customer is responsible for complying with the applicable ZigBee Alliance policies. See http://www.zigbee.org.
This Chipcon product contains Flash memory code protection. However, Chipcon does not guarantee the security of this protection. Chipcon customers using or selling these products with program code do so at their own risk and agree to fully indemnify Chipcon AS for any damages resulting from the use or sale of such products.
Chipcon believes that the Flash memory protection used in this product is one of the most secure in the market today when used in the intended manner and under normal conditions. However, there might be methods to breach the code protection feature. Neither Chipcon nor any other semiconductor manufacturer can guarantee the security of their code protection. Code protection does not mean that we are guaranteeing the product as “unbreakable”.
This Chipcon product contains hardware AES encryption. Chipcon does not guarantee the security of the key protection or the security of the encryption scheme. Chipcon customers using or selling products with AES do so at their own risk and agree to fully indemnify Chipcon AS for any damages resulting from the use or sale of such products.
It is the Chipcon customer's responsibility to ensure that sale or export/import of products including this Chipcon product with AES encryption is sold with the required export/import licenses, if necessary, and does not violate any applicable export/import and/or other trade restrictions.
4.4 Trademarks
SmartRF® is a registered trademark of Chipcon AS. SmartRF® is Chipcon's RF technology platform with RF library cells,
modules and design expertise. Based on SmartRF as full custom ASICs based on customer requirements and this technology.
All other trademarks, registered trademarks and product names are the sole property of their respective owners.
®
technology Chipcon develops standard component RF circuits as well

4.5 Life Support Policy

This Chipcon product is not designed for use in life support appliances, devices, or other systems where malfunction can reasonably be expected to result in significant personal injury to the user, or as a critical component in any life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. Chipcon AS customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Chipcon AS for any damages resulting from any improper use or sale.
© 2006, Chipcon AS. All rights reserved.
CC2431 PRELIMINARY Datasheet (Rev. 1.01) SWRS034A Page 13 of 13
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty . Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products Applications
Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive
DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Low Power Wireless www.ti.com/lpw Telephony www.ti.com/telephony
Video & Imaging www.ti.com/video Wireless www.ti.com/wireless
Mailing Address: Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2007, Texas Instruments Incorporated
Loading...