ST SimpleMAC STM32W108 Series User manual

August 2012 Doc ID 16995 Rev 10 1/54
UM0893
User manual
STM32W108xx SimpleMAC library
1 Introduction
The STM32W108 SimpleMAC (media access control) library provides a set of APIs to
access the lower-MAC function of the STM32W108HB, STM32W108CB, STM32W108C8,
STM32W108CZ and STM32W108CC microcontrollers (STM32W108xx). These devices
integrate a 2.4 GHz IEEE 802.15.4-compliant transceiver featuring 16 channels and
supporting 250 Kbps transfers. The SimpleMAC library is designed to run on all
STM32W108 family devices. In addition, the SimpleMAC library will allow developing
specific stacks based on the IEEE 802.15.4 standard.
This document provides information on:
●IEEE 802.15.4 protocol
●STM32W108 SimpleMAC library features
●How to build and run STM32W108 SimpleMAC demonstration applications
●How to design an application using the STM32W108 SimpleMAC library APIs
Table 1 lists the microcontrollers and tools concerned by this user manual.
Figure 1. STM32W108 SimpleMAC library
Note: The term application board refers to the STM32W108xx boards delivered with all available
STM32W108xx kits. This term is not used to refer to the STM32-Primer2 + MB850
platforms. For more information, visit the STM32W 32-bit RF microcontroller web pages at
www.st.com/stm32w. These web pages provide full access to all STM32W108xx resources
(kits, software packages and documents).
Table 1. Applicable products and tools
Type Part numbers/product sub-classes
Microcontrollers STM32W108xx
Evaluation tools to MCUs
STM32W-EXT
STM32W-SK
STM32W-RFCKIT
MS18162V1
Customer Application
Network Layer (Optional)
IEEE 802.15.4 Upper MAC (Optional)
IEEE 802.15.4 Simple MAC
STM32W108 Device
Customer code
Librairies provided to ST
by customers
Silicon
www.st.com

Contents UM0893
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Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 IEEE 802.15.4 protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 IEEE 802.15.4 networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 IEEE 802.15.4 device addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 PHY and MAC IEEE 802.15.4 protocol layers . . . . . . . . . . . . . . . . . . . . . . 8
2.3.1 IEEE 802.15.4 PHY layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2 IEEE 802.15.4 MAC layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 STM32W108 SimpleMAC library overview . . . . . . . . . . . . . . . . . . . . . . 14
3.1 IEEE 802.15.4 PHY layer supported features . . . . . . . . . . . . . . . . . . . . . 14
3.2 IEEE 802.15.4 MAC supported features . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.3 SimpleMAC library API naming conventions . . . . . . . . . . . . . . . . . . . . . . 15
3.4 SimpleMAC Library APIs classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4 STM32W108 SimpleMAC demonstration applications . . . . . . . . . . . . 16
4.1 SimpleMAC sample demonstration application . . . . . . . . . . . . . . . . . . . . 16
4.1.1 IAR project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1.2 Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1.3 Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.4 Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.5 LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.6 Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.7 Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.8 Serial commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1.9 Running the sample demonstration application on the STM32-Primer2
with an MB850 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2 SimpleMAC PC sun GUI application . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2.1 Run the SimpleMAC sun PC applet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2.2 Build, download and run the sample planet application on the
application board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.2.3 Set up a star network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3 SimpleMAC talk demonstration application . . . . . . . . . . . . . . . . . . . . . . . 29
4.3.1 IAR project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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4.3.2 Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.3.3 Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.3.4 Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3.5 LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3.6 Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3.7 Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.4 SimpleMAC mouse demonstration application . . . . . . . . . . . . . . . . . . . . . 32
4.4.1 IAR projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.4.2 Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.4.3 Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.4.4 Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.4.5 LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.4.6 Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4.7 Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.5 SimpleMAC OTA bootloader demonstration application . . . . . . . . . . . . . . 34
4.5.1 IAR project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.2 Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.3 Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.4 Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.5 LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.5.6 Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.5.7 Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.6 SimpleMAC nodetest application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.6.1 Building and downloading the SimpleMAC nodetest application . . . . . . 38
4.6.2 How to use the SimpleMAC nodetest application commands . . . . . . . . 38
5 Designing an application using the SimpleMAC Library APIs . . . . . . 39
5.1 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5.2 Configuring the radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.2.1 Radio sleep and wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.2.2 Calibrating the radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.2.3 Setting radio channel, power level and power mode . . . . . . . . . . . . . . . 41
5.3 Transmitting packets and managing transmit callbacks . . . . . . . . . . . . . . 42
5.3.1 Configuring the radioTransmitConfig variable . . . . . . . . . . . . . . . . . . . . 42
5.3.2 Setting and transmitting a packet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.3.3 ISR callbacks for packet transmission . . . . . . . . . . . . . . . . . . . . . . . . . . 44

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5.3.4 SFD event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.4 Receiving packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.4.1 Configuring radio filters for packet reception . . . . . . . . . . . . . . . . . . . . . 45
5.4.2 ISR callbacks for packet reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.5 Configuring the coordinator filter mode . . . . . . . . . . . . . . . . . . . . . . . . . . 48
5.6 Radio AES security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.7 Radio MAC timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.8 Other radio features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.8.1 Radio energy detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.8.2 Radio CCA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.8.3 Radio packet trace interface (PTI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.8.4 Send a tone or a carrier wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
7 List of acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

UM0893 List of tables
Doc ID 16995 Rev 10 5/54
List of tables
Table 1. Applicable products and tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Table 2. IEEE 802.15.4 PHY parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 3. General MAC frame format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 4. PHY frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 5. Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 6. Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 7. Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 8. LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 9. Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 10. Serial commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 11. Detailed command description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 12. STM32-Primer2 SM SUN menu versus input commands. . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 13. SimpleMAC sun PC applet command options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 14. Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 15. Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 16. Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 17. LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 18. Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 19. Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 20. Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 21. LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 22. Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 23. Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 24. Boards supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 25. Serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 26. Support commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 27. LED description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 28. Button description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 29. RadioTransmitConfig members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 30. Packet FCF configuration as 0x0821 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 31. FCF field of the packet sent to a coordinator node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 32. List of references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Table 33. List of acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Table 34. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

List of figures UM0893
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List of figures
Figure 1. STM32W108 SimpleMAC library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Peer-to-peer topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 3. Star topology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 4. PHY and MAC layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 5. Device-to-coordinator communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 6. Coordinator-to-device communications in beacon-enabled networks . . . . . . . . . . . . . . . . 11
Figure 7. Coordinator-to-device communications in non beacon-enabled networks . . . . . . . . . . . . . 12
Figure 8. Star network created by sun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 9. Planet associated to sun. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 10. Data sent from planet to sun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 11. Sun plus 5 planets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 12. Network down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 13. SimpleMAC sun PC applet flash image check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 14. SimpleMAC sun node forms an IEEE 802.15.4 network . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 15. Planet device joining the network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 16. Planet sending data to the sun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 17. Sun node with 5 planets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

UM0893 IEEE 802.15.4 protocol
Doc ID 16995 Rev 10 7/54
2 IEEE 802.15.4 protocol
The IEEE 802.15.4 is a standard which specifies the physical layer (PHY) and the media
access control (MAC) layer for low-rate wireless personal area networks (LR-WPANs).
The main features are as follows:
●Channel access via carrier sense multiple access with collision avoidance (CSMA-CA)
●Optional time slotting and network beaconing
●Message acknowledgement
●Multilevel security
●Suitable for long battery devices, with selectable latency to match different power
requirements (sensors, remote monitoring, …)
The IEEE 802.15.4 standard distinguishes between two types of devices:
– Full function devices (FFD)
Full function devices can be common nodes or coordinators of personal area
networks (PANs). They can communicate with any device connected to the
network and relay messages. FFD devices are suitable for any type of network
topology.
– Reduced function devices (RFD)
Reduced function devices are simple devices with limited resources and
communication capabilities. They can only communicate with FFDs and can never
act as coordinators. RFD devices are only suitable for star networks.
2.1 IEEE 802.15.4 networks
Two types of network topologies are supported:
●Peer-to-peer networks where each device can communicate with any other device as
long as they are in range of one another.
Figure 2. Peer-to-peer topology

IEEE 802.15.4 protocol UM0893
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●Star networks where communications are established between devices and a single
central controller, called the PAN coordinator.
Figure 3. Star topology
2.2 IEEE 802.15.4 device addressing
A unique PAN identifier is assigned to each independent PAN built on a channel.
All devices connected to the network have a unique 64-bit extended address. This address
is used for direct communications through the PAN. A device can also use a short 16-bit
address which is allocated by the PAN coordinator when the device is associated to the
network.
2.3 PHY and MAC IEEE 802.15.4 protocol layers
Figure 4 shows the IEEE 802.15.4 MAC and PHY layers.
Figure 4. PHY and MAC layers

UM0893 IEEE 802.15.4 protocol
Doc ID 16995 Rev 10 9/54
2.3.1 IEEE 802.15.4 PHY layer
The PHY layer manages the physical RF transceiver. It is also in charge of the following
tasks:
●Activating and deactivating of the radio transceiver
●Energy detection for the current channel
●Indicating link quality for the received packets
●CCA for the CSMA-CA
●Selecting channel frequency
●Data transmission and reception
The standard specifies two PHY layers:
●868/915 MHz direct sequence spread spectrum (DSSS) PHY
– One 20 Kbps channel in the European 868 MHz band
– Ten 40 Kbps channels in the 915 MHz ISM band (from 902 to 928 MHz)
●2 450 MHz DSSS PHY supporting sixteen 250 Kbps channels in the 2.4 GHz band
IEEE 802.15.4 PHY CCA
The following CCA modes are supported:
●CCA mode 1: energy above threshold (lowest)
●CCA mode 2: carrier sense (medium)
●CCA mode 3: carrier sense with energy above threshold (strongest)
Table 2. IEEE 802.15.4 PHY parameters
Parameter 2.4 GHz PHY 868/915 MHz PHY
Sensitivity @ 1% PER -85 dBm -92 dBm
Receiver maximum input level -20 dBm
Adjacent channel rejection 0 dB
Alternate channel rejection 30 dB
Output power (lowest maximum) -3 dBm
Transmit modulation accuracy EVM < 35% for 1000 chips
Number of channels 16 1/10
Channel spacing 5 MHz Single-channel at 2 MHz
Transmission rates:
Data rate
Symbol rate
Chip rate
250 kbps
62.5 ksymbol/s
2 Mchip/s
20/40 kbps
20/40 ksymbol/s
300/600 kchip/s
Chip modulation O-QPSK with half-sine pulse
shaping
BPSK with raised cosine
pulse shaping

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IEEE 802.15.4 PHY link quality indication (LQI)
The LQI characterizes the strength and/or quality of a received packet. The measurement
may be implemented using:
●Receiver energy detection
●Signal-to-noise ratio estimation
2.3.2 IEEE 802.15.4 MAC layer
The MAC layer is in charge of the following tasks:
●Generating network beaconing for devices acting as PAN coordinators
●Synchronizing with the beacons
●Supporting PAN association and dissociation
●Supporting device security
●Using the CSMA-CA for channel access
●Managing the GTS mechanism
●Providing a reliable link between peer-to-peer MAC entities.
IEEE 802.15.4 MAC data transfer
The IEEE 802.15.4 MAC protocol supports two data transfer models that can be selected by
the PAN coordinator:
●The non beacon-enabled mode, in which the MAC is simply ruled by unslotted CSMA-
CA.
●The beacon enabled mode, in which beacons are periodically sent by the coordinator to
synchronize the associated nodes and identify the PAN. Access to the channel is ruled
by slotted CSMA-CA using the superframe structure.
For detailed information about the IEEE 802.15.4 slotted/unslotted CSMA-CA and the
superframe structure, refer to the related IEEE 802.15.4 standard specification.
IEEE 802.15.4 MAC device-to-coordinator data transfer
In beacon-enabled networks, the devices search for the beacon to synchronize with the
superframe structure. They then transmit data using slotted CSMA-CA.
In non beacon-enabled networks, the devices simply transmit data using unslotted CSMA-
CA.

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Figure 5. Device-to-coordinator communications
IEEE 802.15.4 MAC coordinator-to-device data transfer
In beacon-enabled networks, the coordinator indicates in the beacon that data is pending.
The device periodically listens to the beacons and transmits a data request MAC command
using slotted CSMA-CA if necessary.
Figure 6. Coordinator-to-device communications in beacon-enabled networks
In non beacon-enabled networks, devices transmit a data request MAC command using
unslotted CSMA-CA. If a coordinator data transmission is pending, the coordinator transmits
a data frame using unslotted CSMA-CA. Otherwise, the coordinator transmits a data frame
containing a zero-length payload. Refer to IEEE 802.15.4 general MAC frame format for a
description of the MAC frame.

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Figure 7. Coordinator-to-device communications in non beacon-enabled networks
IEEE 802.15.4 general MAC frame format
The MAC frame is composed of a MAC header (MHR), a MAC payload, and a MAC footer
(MFR). The MHR is composed of fixed fields. The address fields are optional.
The MAC frame control field (FCF) has the following structure:
Table 3. General MAC frame format
2 bytes 1 byte 0/2 bytes 0/2/8 bytes 0/2 bytes 0/2/8
bytes Variable 2 bytes
Frame
control
field
(FCF)
Sequence
number
Destination
PA N
identifier
Destination
address
Source
PA N
identifier
Source
address Frame
payload FCS
Addressing fields
MHR MAC
payload MFR
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Source
addressing mode Reserved Destination
addressing mode Reserved Intra-
PA N
Ack.
request
MAC
frame
pending
Security
enabled MAC frame type
Bits [15:14] Source addressing mode
00: PAN identifier and address field are not present.
01: reserved
10: Address field contains a 16-bit short address.
11: Address field contains a 64-bit extended address.
Bits [12:13] Reserved
Bits [11:10] Destination addressing mode
00: PAN identifier and address field are not present.
01: reserved
10: Address field contains a 16-bit short address.
11: Address field contains a 64-bit extended address.
Bits [7:9] Reserved

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IEEE 802.15.4 PHY frame format
Table 4 shows the PHY frame structure.
●The preamble field is used by the transceiver to perform chip and symbol
synchronization with an incoming message. The preamble is composed of 32 binary
zeros.
●The SFD field (start-of-frame delimiter) is an 8-bit field indicating the end of the
synchronization preamble and the start of the packet data. The SFD must be equal to
10100111b.
●The frame length field is 7-bit long. It specifies the total number of bytes contained in
the PHY payload field (PSDU). Its value ranges from 0 to 127.
●The PHY payload field (PSDU) contains the MAC frame.
For more details about the PHY and MAC frames, refer to the IEEE 802.15.4 standard
specification.
Bit 6 Intra-PAN
1: frame to be sent within same PAN
0: frame to be sent to another PAN
Bit 5 Acknowledge request
1: device sends an acknowledgment frame when it receives a valid frame
0: device does not send an acknowledgment frame when it receives a valid frame
Bit 4 MAC frame pending
1: sender device has additional data to send to the receiver
0: sender device does not have any more data for the receiver
Bit 3 Security enabled
1: frame is cryptographically protected by the MAC layer
0: frame is not cryptographically protected by the MAC layer
Bits [2:0] MAC frame type
000: Beacon 011: MAC command
001: Data 100: Reserved
010: Ack 111: Reserved
Table 4. PHY frame format
4 bytes 1 byte 1 byte Variable
Preamble SFD Frame length
(7 bits)
Reserved
(1 bit)
PHY payload
field (PSDU)
SHR PHR PHY payload

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3 STM32W108 SimpleMAC library overview
This section describes the STM32W108 SimpleMAC library features:
●IEEE 802.15.4 PHY features supported by the library
●IEEE 802.15.4 MAC features supported by the library
●SimpleMAC library APIs naming conventions and classes.
3.1 IEEE 802.15.4 PHY layer supported features
The SimpleMAC library supports the following IEEE 802.15.4 PHY features:
●Radio channel selection on 2.4 GHz band
●Radio calibration
●Transmission power control
●Boost mode control
●Selection of alternate transmission path for external power amplifier
●Radio sleep and wakeup control
●Time stamp of received and transmitted packets
●LQI and RSSI for received packets
●Transmit single carrier frequency (diagnostic function)
●Transmit continuous stream of random symbols (diagnostic function)
●Automatic seeding pseudo random number generator using hardware random number
source
3.2 IEEE 802.15.4 MAC supported features
The SimpleMAC library supports the following IEEE 802.15.4 MAC features:
●Transmit functions
– Unslotted CSMA transmit support including CCA
– Backoff periods determined by pseudo random number generator
– CRC generation and CRC data insertion into packets
– Automatic reception and verification of acknowledgement
●Receive functions
– Packet reception with hardware filtering, correlator error and CRC checking
– Ability to set node addresses and PAN identifier (for receive filtering only)
– Hardware filters fully exposed
– Automatic transmission of acknowledgement with software control over frame
pending indication
– Promiscuous mode
– Ability to enable/disable receivers

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3.3 SimpleMAC library API naming conventions
The following naming conventions are used:
●General prefix
All SimpleMAC APIs are prefixed with “ST_” followed by the general API family (e.g.
Radio, AES).
●Callback suffix
The functions which are implemented in the application and called from the
SimpleMAC library are suffixed with “Callback”.
●ISR callback suffix
The functions which are implemented in the application and called from the
SimpleMAC library in interrupt context are suffixed with “IsrCallback”.
●ISR suffix
The functions which are implemented in the SimpleMAC library and must be called by
the application in response to hardware events are suffixed with “Isr”.
3.4 SimpleMAC Library APIs classes
The following API classes are supported:
●Radio power state control APIs which control the overall radio initialization and power
state.
●Radio channel APIs which control channel selection and calibration.
●Radio transmit APIs which control the transmission of packets.
●Radio receive APIs which control the reception of packets.
●Radio cryptography APIs which provide an interface to the hardware AES coprocessor.
●Radio MAC timer APIs to interface with the MAC timer.
●Radio miscellaneous APIs which perform MAC diagnostic and configuration.
For a detailed description of the SimpleMAC library APIs, refer to the STM32W108
SimpleMAC Library APIs documentation.

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4 STM32W108 SimpleMAC demonstration applications
Four simpleMAC demonstration applications are delivered within the SimpleMAC software
library package which is available from the STM32W 32-bit RF microcontroller web pages at
www.st.com/stm32w:
●SimpleMAC sample demonstration applications (sun and planet roles)
●SimpleMAC talk demonstration application
●SimpleMAC mouse demonstration application
●SimpleMAC OTA bootloader demonstration application
●SimpleMAC nodetest application
The demonstration applications designed to run on an application board may require a
serial communication interface.
The following subsections provide a description of the building and running steps of the
demonstration applications using the IAR projects delivered within the SimpleMAC software
library package as a reference. The available workspaces provide reference examples for
the STM32W108CC boards.
4.1 SimpleMAC sample demonstration application
This is an example of an RF application that shows an 802.15.4 star topology using the
STM32W108 microcontroller.
4.1.1 IAR project
To use the project with IAR Embedded Workbench for ARM, follow the instructions below:
1. Open the Embedded Workbench for ARM.
2. From the File > Open > Workspace menu, open the related IAR workspace.
3. Select the configuration that you want to build.
4. Select Project > Rebuild All to recompile and link the entire application.
5. To launch a debug session, connect the IAR Jlink to the JTAG connector (P1) in your
board.
6. Select Project > Download and Debug. The related binary image is downloaded into
the STM32W108CC Flash memory and the interactive debug session is started.
7. Connect the application board to a PC USB port. Open a hyperterminal on the
corresponding USB virtual COMx port with the configuration, as described in
Section 4.1.4: Serial I/O.
4.1.2 Jumper settings
Table 5. Jumper settings
Jumper name All configurations
JP1, if available Irrelevant
P1, if available 1-2 (battery) 5-6 (USB)

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4.1.3 Boards supported
X = supported
- = not supported
NA = not applicable
Table 6. Boards supported
Board name Board
revision STM32W108xB STM32W108CC Sun Planet
Primer2 + MB850 A A X NA X -
MB851 A,B,C X NA X X
DNA XXX
MB954 A,B X NA X X
CNA XXX
MB950A + MB953 MB953A X NA X X
MB953B NA X X X
MB951 AXNAXX
BNA XXX

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4.1.4 Serial I/O
The application listens for commands sent over the serial port. The serial port configuration
is:
4.1.5 LED description
4.1.6 Button description
4.1.7 Usage
This demonstration represents an Application Framework which sets up a basic star
topology and supports parent and child roles. To prevent name collisions with other
software, applications, and implementations, the parent role is called "sun" and the child role
is called "planet". These roles are implemented using specific definitions: SUN_ROLE and
PLANET_ROLE.
Executing the form command on a node loaded with the sun image provokes the node to
form a network. Executing the form command, on a node loaded with the planet image,
provokes the node to join the network formed by the sun node. Executing the leave
command provokes each node to leave the network. There cannot be multiple suns on the
same PAN ID.
Table 7. Serial I/O
Parameter name Value Unit
Baud rate 15200 bit/sec
Data bits 8 bit
Parity None bit
Stop bits 1 bit
Table 8. LED description
LED name STM32W108xB_SUN STM32W108xB_PLANET
D1 Not used Not used
D3 Not used – On when joined a network
– Off when not joined
Table 9. Button description
Button name STM32W108xB_SUN STM32W108xB_PLANET
S1 Not used Join network
S2 If available Not used
S3 If available Not used
S4 If available Not used
S5 If available Not used

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The sample applications demonstrate:
●Management of a simple direct transmission queue
●Management of a simple indirect transmit queue including interaction with the receive
ISR, in order to handle the setting of the ACK frame pending bit, in response to a data
poll
●Sleepy planets automatically send the radio to sleep when there is no more data to
transmit
●Retry of packet on ACK failure
●Active search for a sun implemented as simple blocking code
●Energy search for a channel with low activity implemented as simple blocking code
●Capture of transmit SFD time and insertion of time value into packet payload.
●Conversion of correlator error count to LQI
●Planet deep sleeping
Note: All references to "sleep" and "sleepy" refer to deep sleep operations.
4.1.8 Serial commands supported
X = supported
- = not supported
Note: All commands are invoked as a single character.
Table 10. Serial commands supported
Command Description STM32W108xB_SUN STM32W108xB_PLANET
i Display status information X X
f Form a network X -
j Join a network - X
l Leave a network X X
s Send data X X
c Clear indirect transmit queue X -
pPollfordata - X
r Adjust send/poll rates X X
t Display the planet table - X
o Enter OTA bootloader mode X X
u Enter Uart bootloader mode X X
? Display this help menu X X

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Table 11. Detailed command description
Command Description
i
Display status information displays the status of the node including information
such as:
–Networkrole
– Radio on/off state
– In or out of a network
– Channel
–Power
–EUI64
–PANID
– Node ID
– Send rate
– Poll rate
f
Form a network can only be executed while not already in a network. To form the
network, the node first initializes all persistent states then loops over all channels
searching for the channel with the lowest energy. The node dwells on each channel
taking multiple energy readings and records the highest energy level seen on every
channel. After obtaining a maximum energy reading for each channel, the node
selects the channel with the lowest maximum energy reading and configures itself
for that channel. The node then assigns itself a random PAN ID and assigns itself
the short address (node ID) 0x0000.
j
Join a network can only be executed while not already in a network. To join the
network, the node first initializes all persistent states then loops over all channels
searching for a channel with a sun. On each channel, the node transmits a sun
search broadcast packet and then waits for 200 ms for a sun available response.
If the node does not receive a sun available broadcast response after 200 ms, it
moves on to the next channel. If the node never receives a sun available response
or cannot complete the join process on any channel, the node indicates this fact to
the user and the user must invoke the join network command to try again.
The sun only sends the sun available response if there is room in the sun's planet
table. If the node does receive a sun available response, the response includes the
sun's PAN ID as the source PAN ID. If the node receives more than one sun
available response, the node tries to join the first response it receives.
Multiple suns on the same PAN ID are not valid, and there is no collision detection
for this situation. The planet sends a join request unicast packet using long
addressing and the sun's PAN ID. When the sun receives the join request, the sun
attempts to place to the planet in its planet table. The planet table is a fixed size. If
there is no room in the planet table, the sun responds with a join denied unicast
packet. If there is room in the planet table, the sun allocates a new short ID to the
planet, puts the planet in its planet table, and responds with a join accepted unicast
packet. There is no error detection if the join process fails before the join accepted
or denied packet has been received.
The sun does not remove planets from its planet table unless the planet specifically
sends a leaving network packet.