AN2773 Freescale Semiconductor / Motorola, AN2773 Datasheet - Page 3

• Manufacturer Part Number: AN2773
• Description: Switch Demonstration For the 802.15.4 and Zigbee MAC Layer
• Manufacturer: Freescale Semiconductor / Motorola

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This section describes the configuration setup which consists of the commands necessary to connect two
units and maintain the link (MLME). This section also provides a description of the data transmission
(MCPS).
3.1
The switch demonstration uses only the basic 802.15.4 MAC primitives. After users start the scan, the
Device automatically associates if a Coordinator was found. After the Association, the Device begins to
poll the Coordinator. In the Switch Demonstration, the polling scheme is very aggressive because it always
sends a new poll request each time the previous one has completed unless the low power feature is included
(See
placed in a low power state for 160ms just before the poll request is sent.
3.2
On the 802.15.4 MAC layer, data from the Device to the Coordinator can be sent directly. Data from the
Coordinator should be sent indirectly. That is, the Device polls the Coordinator. When sending a data
packet from the Device to the Coordinator, the Device in the Switch Demonstration briefly stops the
polling scheme. This is not required, but it is the expected behavior. Switch Demonstration data
transmission is controlled by event flags. A flag is set when the user wants to send a packet (S4 is pressed).
This flag is for a direct transmission and is checked every time a poll confirm is received. If set, the Device
sends a data packet and then starts polling again when the data confirm message is received. For indirect
data transmission, the flag is checked in the main loop. When the flag is set, the main loop sends a message
to the MCPS handler, which then sends the data when it is polled by the Device.
Freescale Semiconductor
Section 4.2.7, “Low
802.15.4 MAC Level
Figure 1
Configuration setup
Data transmission
shows the data transmission sequence.
Power”). In the low power scenario, the MCU and the MC13192/MC13193 are
Switch Demonstration, Rev. 1.1
802.15.4 MAC Level
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