AN2103 Freescale Semiconductor / Motorola, AN2103 Datasheet - Page 40

• Manufacturer Part Number: AN2103
• Description: Local Interconnect Network (LIN) Demonstration
• Manufacturer: Freescale Semiconductor / Motorola

40
Application Note
4.3.3
Sleep Mode
Freescale Semiconductor, Inc.
Sleep mode is the demo’s low power mode. It is entered when the
master transmits the SLEEP identifier (0x80). Each slave receives
the command and jumps to the sleep message handler. The handler
disables the voltage regulator by driving the LIN I/F into sleep mode.
Any node can be brought out of sleep mode by an external switch
(switches around the circumference of the clock face) or a wake-up
message (see protocol specification for details) detected on the LIN
bus. The slave that is woken up transmits the wake-up message onto
the bus, which wakes up the master and the other nodes.
Each slave distinguishes between a wake-up (switch on voltage
regulator) and a normal power up sequence, by detecting if the
master is present on the bus (master will be communicating on bus
for standard power up sequence). The master transmits an ALIVE
(0x0F) message every 150ms to signal its presence. If a slave
detects an ALIVE message it assumes that it is a power up
sequence. If the ALIVE is not detected within 200ms the slave
assumes that it has woken up and subsequently transmits a wake-up
message to the network.
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
AN2103