P MA 7 1 x x/ P M A51 x x
SmartLEWISTM MCU
RF Transmitter FSK/ASK 315/434/868/915 MHz
Embedded 8051 Microcontroller with Function Library in ROM
Applic atio n Whi tep a per
May 2009
Wirel ess Con trol
Edition May 2009
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2009 Infineon Technologies AG
All Rights Reserved.
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PMA71xx/ PMA51xx
SmartLEWIS MCU
Table of Contents
Abstract
4
1
Introduction ........................................................................................................................................4
2
PMA as a Wireless Remote Control .................................................................................................5
3
PMA as a Contactless Sensor...........................................................................................................5
4
Periphal Block LF Receiver...............................................................................................................6
5
SW Function Library and Framework ..............................................................................................6
6
PMA Development Tools ...................................................................................................................7
7
Product Family, Fundamental Data and Chip Housing ..................................................................8
8
Summary .............................................................................................................................................9
Application Whitepaper
3
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
Abstract
TM
SmartLEWIS
MCU – The flexible single-chip solution for wireless remote controls and wireless
sensing. Wireless data transmission in the license-free ISM frequency bands below 1 GHz is very popular
thanks to its low power consumption, low costs and comparably simple implementation. The strong rise in its
deployment in established applications, such as in remote controls where it is used as a substitute for infrared
technology, is now being flanked by many new applications where it is enabling new levels of ergonomics and
new functionality.
By Martin Gotschlich, Infineon Technologies AG
1
Introduction
As the first product in the new SmartLEWIS™ MCU family, the PMA 7110 is predestined for easy
implementation of a multitude of attractive wireless transmission applications. The highly integrated circuit
monolithically combines an 8051 microcontroller, an RF transmitter and other interesting peripheral blocks on a
single semiconductor chip. In particular, the analog-to-digital converter for connection of analog sensors and a
125-kHz LF receiver are noteworthy. The analog-to-digital converter is characterized by an additional
configuration area for amplification of the three symmetrical inputs. The LF receiver is suitable for contactless
triggering of transmission processes and for contactless configuration (e.g., personalization or charging with
credit). An extensive library of SW functions is integrated into the ROM by default, thereby saving valuable flash
memory. Typical applications can be implemented with comparatively little programming effort.
125 kHz LF
trigger &
data in
16-bit CRC
generator /
checker
RAM
256 B
PP9
Flash sector 0
6 kB user code
digital IO
GPIO
I2C
SPI
ROM
function library
PP0
Flash sector 1/2
2 x 128 kB data
EEPROM emulation
PMA 71xx / 51xx
8-bit pseudo
random
number
generator
MHz
315 dBm
5
434
8
868
10
915
LF Rx
125 kHz
4 timers
16 bit
µC 8051
RF Tx
ASK/FSK
PLL
high sens. 1
high sens. 2
Manchester /
bi-phase
encoder
ADC
10bit
std. sens.
battery voltage &
temperature
sensor
system controller
interrupt & wake-up logic
power management
brownout
detector
watchdog
RC
oscillator
12MHz
RC
oscillator
2 kHz
RF XTAL
oscillator
18 … 20 MHz
1.9 … 3.6 V
Figure: Block diagram of the PMA 7110
The strengths of the PMA 7110 can be particularly demonstrated in two application segments as follows:
conventional remote controls for control of an appliance or a system via an RF wireless link and wireless
sensors, in which diverse test variables are autonomously monitored and with which measured values are sent
to a receiver in the event of particular states or events. In addition, identification applications (e.g. smart tagging)
can also be realized.
Application Whitepaper
4
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
2
PMA as a Wireless Remote Control
Wireless remote controls in the free sub-1-GHz frequency ranges are finding ever greater use in a wide number
of applications. These applications can be implemented with the PMA 7110 as a single-chip solution in the
simplest way possible, but in which even demanding functions know no boundaries thanks to the extensive
integrated peripheral blocks and the free programmability.
Remote Keyless Entry (RKE) applications have been standard in the automotive sector for many years. Such
applications can be implemented with the automotive-qualified derivative PMA 5110. Two functions in the PMA
family play a special role in the security of the application as follows: to generate continuously changing key
codes ('rolling codes'), the EEPROM emulation allows continuous storage of information in active operation (for
each key action) in a reserved part of the nonvolatile flash memory. The encryption of the transmitted
information is realized using the license-free AES algorithm (Advanced Encryption Standard), which is included
as a basic feature in the extensive software library in the chip's ROM along with many other functions (further
details are given below). Infineon also provides additionally an alternative encryption example code based on
the license-free XTEA algorithm (Extended Tiny Encryption Algorithm).
A pronounced growth in the number of applications for wireless remote controls can be seen in the consumer
sector. The replacement of infrared remote controls in the entertainment and home electronics market has a key
role to play in this growth. Apart from the multiroom remote controls (e.g., settop boxes in neighboring rooms),
wireless remote controls – also acting as conventional infrared replacements – provide considerable additional
ease of use because the remote controls no longer need to be directed toward the receiver. The ten free
programmable digital inputs/outputs (General Purpose Input/Output, GPIOs) of the PMA 7110 can be directly
linked with up to 30 buttons (and even up to 55 buttons with additional diodes). Eight of the ten lines can also be
configured for wakeup signals in which case the remote control after sending the signal immediately switches to
standby mode with very low power consumption; the remote control remains inactive until a button is pressed
again. Depending on the design of the antenna used, the power consumption can be lower than that of any
infrared remote controls operating at the same distance, even during transmission. This means that markedly
smaller batteries can be used, which, on the one hand, enables new design possibilities for remote control
housings and, on the other hand, that batteries may not need to be changed for the entire lifetime of a product.
Oscillator
open loop
antenna
27mm
3V CR2032
passive antenna
matching network
Infineon
in-circuit
PMA5105 programming
connector
43mm
Figure: PMAfob – A Remote Keyless Entry application example with PMA 5105
3
PMA as a Contactless Sensor
Contactless sensors can be very flexibly arranged, thus providing greater ease of use and simpler installation on
the one hand, while enabling even unusual measurements to be performed on the other hand – for example,
operation on moving objects such as rotating machine parts. The low power consumption of the PMA 7110 is
also one of the key design criteria in this case because the battery capacity varies according to the specified
target lifetime of the application, which in turn is important for the dimensions, weight and finally for the cost of
the whole sensor module.
Application Whitepaper
5
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
While sensors with a digital interface (e.g. SPI) can be easily connected to the GPIOs of the PMA 7110, the chip
also allows a wide variety of inexpensive analog sensors to be operated in the total of three channels of the
analog-to-digital converter (ADC). The flexible configuration of the symmetric inputs also enables high levels of
input amplification so that additional preamplifiers can be dispensed with in many cases.
A number of strategies could be employed to minimize the power consumption of the application. For example,
a measured value is only to be transmitted over the air interface if particular threshold values are exceeded.
Extremely long battery lifetimes can be realized if the contactless sensor is only 'woken up' by wireless
activation as required by means of the LF receiver described in greater detail below. Along with the two timers in
the 8051 microcontroller core, there are two further timers that can be used for complex timing scenarios.
4
Periphal Block LF Receiver
The LF receiver is suitable for receiving amplitude-modulated 125-kHz signals that are magnetically induced in
a receiver coil. Since the receiver is only activated by means of the induced energy, it consumes practically no
power in standby mode. In the most straightforward case, the LF receiver can be used for contactless triggering
of a transmission procedure. To do so, the user employs a 125-kHz transmission signal, a so-called trigger,
activated in the vicinity of the RF transmitter. The RF transmitter responds with measured sensor data or an
identification code. In a similar manner, data can also be sent to the RF transmitter using 125-kHz amplitude
modulation. This function could be used, for example, for contactless calibration of a sensor transmission unit or
for one-time storage of identification codes in the RF transmission device – for example, for customer data at
the point of sale of the device.
5
SW Function Library and Framework
Programming of the 8051-compatible microcontroller (regarded as standard in the industry) in C and Assembler
is itself uncomplicated. Nonetheless, the SW function library stored in ROM in the PMA family allows very
efficient access to all on-chip peripheral functions without a programmer having to know in detail the bits and
bytes of the chip's system architecture. This means that the programmer can very quickly produce complex
applications in relatively few, but very powerful, function calls. The following example of a C main routine shows
how easily an RF (radio frequency) thermometer can be programmed. The SW library functions are indicated in
bold typeface.
void main(void)
{
// determine if reset or wake up
if (!(DSR & BIT_WAKEUP)) {
// after reset
Switch2XTAL();
CalibrateIntervalTimer(1);
ITPR = 5;
// Change clock to external crystal
// Interval frequency 1Hz
// Set to 5sec
} else {
// Wakeup detected, determine which one
if (WUF & BIT_WU_TIMER) {
InitRF(&myRF_Config);
Switch2XTAL();
// Change clock external crystal
VCOTuningLong();
// Selects an appropriate tuning curve for
// the VCO and enables the PLL
RFC |= 0x01;
// Enable PA
MeasureTemperature(&value);
// Measure internal temperature sensor
datagram[TX_TEMPPOS] =value[0] >> 8;
// Prepare datagram
datagram[TX_TEMPPOS+1]=value[0] & 0xFF;
Application Whitepaper
6
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
datagram[TX_TEMPPOS_R] =value[1] >> 8;
datagram[TX_TEMPPOS_R+1]=value[1] & 0xFF;
TransmitRF(datagram,TX_LEN);
// Transmit datagram via RF link
}
}
PowerDown();
// Power down
}
Figure: Example of code for an RF thermometer
Another key advantage of this concept is that the size of the application-specific code can be kept very small
since most of the code is already present in the preprogrammed function library in ROM. Subsequently, the 6KB
flash memory allows considerably more extensive applications to be implemented than in comparable µC
architectures in which the entire program code has to be stored in valuable flash memory. Another benefit
deriving from this architecture is the significant reduction in flash programming times, enabling further cost
efficiencies in the customer's production process.
6
PMA Development Tools
Infineon provides extensive and powerful development tools for all products of the PMA 71xx and 51xx families,
whereby the tooling is universal and independent of the used product variant
The PMA Starter Kit, available for € 49, is especially interesting. The kit contains everything you need for initial
evaluation and creation of uncomplicated applications. Its main component is a USB stick that supports all the
major functions of the PMA 5110 chip, and also features a rechargeable lithium-ion battery to enable mobile
operation of a newly created application.
Figure: PMA Starter Kit with PMA RF USB Stick
This development tool is very easy to use and only a few steps are needed for operation:
•
•
•
•
•
•
Install the SW development tools from KEIL (license-free trial version available for download).
Install the latest PMA Starter Kit software package
Insert the PMA RF USB stick into a free USB port on the PC.
Enter a few lines of C code in the prepared application framework. The powerful functions in the ROM
SW library allow extremely lean source code in which the bits and bytes of the HW architecture do not
have to be considered in detail.
Compile the C source code and then load it into the flash memory of the PMA 7110 via the USB
interface.
Remove the USB stick from the PC and start the new application, which is powered by the rechargeable
lithium-ion battery.
Application Whitepaper
7
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
Secondary, Infineon offers the PMA Evaluation Kit. This enhanced development tool provides highest flexibility
by giving easy access to all pins for detailed measurements and by supporting the ADC and LF receiver
functionality.
For further information on PMA tooling please visit www.infineon.com/pma_tooling
7
Product Family, Fundamental Data and Chip Housing
LF receiver
(125kHz)
Operating
temperature
range
PMA 7106
3-channel,
10-bit ADC
PMA 7105
ASK/FSK UHF
Transmitter
Type
8051 µC +
Flash
The PMA derivatives from the 71xx series are intended for use in industrial and consumer applications and are
designed for an operating temperature range from -40°C to +85°C. The 51xx series is Q100 automotivequalified and can be used in an operating temperature range from -40°C to +125°C. PMA supports the 315,
434, 868 and 915 MHz frequency bands and three different output power levels of 5, 8 and 10 dBm. All
derivatives in the PMA product family are pin-compatible in a standard PG-TSSOP-38 package. Most of the
printed circuit board layout can be left unchanged for product derivatives and country variants with different
frequencies can be realized as mounting options of external components. The functional differences in the PMA
product family refer to the availability of LF receiver and analog-to-digital converter, as shown in the table below:
Target Applications
!
!
!
!
!
-
-40°C to +85°C
- Remote Controls
- Wireless sensors with digital sensor interface
-40°C to +85°C
- Wireless sensors with analog sensor interface
PMA 7107
!
!
-
!
-40°C to +85°C
- Active Tagging / Door opener
- Remote Control with contact-less
configuration
- Wireless sensors with contact-less trigger
and configuration
PMA 7110
!
!
!
!
-40°C to +85°C
- Sophisticated wireless sensors with
contact-less trigger and configuration
PMA 5105
!
!
-
-
-40°C to +125°C
- Applications in rough environment and with
high quality requirements (extended temp.
range and automotive qualification)
- Remote Keyless Entry
PMA 5110
!
!
!
!
-40°C to +125°C
- High end applications in rough environment
and with high quality requirements (extended
temp. Range and automotive qualification)
- Remote Keyless Entry
Table: SmartLEWIS MCU family overview
Figure: PG-TSSOP-38 package
Application Whitepaper
8
May 2009
PMA71xx/ PMA51xx
SmartLEWIS MCU
8
Summary
Owing to the high level of integration, the PMA 71xx/51xx products in the SmartLEWIS™ MCU family enable a
multitude of demanding high-frequency transmission applications on a single-chip basis in the area of wireless
remote controls and wireless sensing. The extensive SW function library significantly accelerates development
times and optimizes application quality.
For further information, please visit www.infineon.com/PMA
Application Whitepaper
9
May 2009
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
B142-H9393-X-X-7600