Texas Instruments CC2431 Datasheet

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CC2431

System-on-Chip for 2.4 GHz ZigBee

™/

Applications

• ZigBee™ systems

• 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:

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

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

Wait

LOCENG.DONE=1

yes

Read LOCX, LOCY

and LOCMIN

LOCENG.EN=0

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

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

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

Path Loss (dB)

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

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

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)

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.

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.

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.

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Texas Instruments CC2431 Datasheet

Specifications and Main Features

Frequently Asked Questions

User Manual

4.2 Product Status Definitions

4.5 Life Support Policy