ISL40 Datasheet, PDF (5/12 Pages) Yamar Electronics Ltd. – Independent DC-LIN Slave For Asynchronous Communication Over Noisy Lines

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Sync break
Sync Field
0x3C
Zero byte/bytes
Checksum
Figure 3.5 Sleep message
Change Frequency message:
This type of message consists of 5 bytes - sync break, sync field, “FE” Hex, “00” Hex and checksum.
The change frequency message identifier is “FE” Hex and the following data byte “00”Hex.
Upon reception of sync break, sync field, “FE” Hex and “00” Hex bytes the frequency changes from F1
to F0 or vise versa.
Sync break
Sync Field
0xFE
Zero byte/bytes
Checksum
Figure 3.6 Frequency Change message
3.2 Power Management
The device features Sleep mode for power saving. Entering Sleep and waking up are done either
locally by dedicated pins, or remotely through activity over the bus.
3.2.1 Entering Sleep mode
The ISL40 can enter sleep mode in the following ways:
1. Local device lowers its nSleep pin.
2. Remote master SIG40 device can enter the ISL40 device into Sleep Mode from Normal mode by
transmitting the remote sleep message.
3. The AutoSleep pin is high and no reception occurred for about 8 seconds.
3.2.2 Remote wake up process
The ISL40 can wakeup by a remote SIG40 master or ISL40 device transmits a wakeup message over
the bus. During Sleep Mode, the ISL40 wakes up periodically to sense the bus for activity every
32mSec. If a wakeup message is detected, the ISL40 device raises pin INH and lowers pin HDO. If
nSleep pin is low upon remote waking up, the local device that lowered it must raise the nSleep back
high. Figure 3.6 shows the signals description.
DC-BUS
INH
HDO
msg. detected
Wakeup Message
Standby
Normal mode
Figure 3.7 - Wakeup from bus message
3.2.3 Wakeup from pin Wake
A transition on pin Wake (caused by an external switch of the application) is used to wake the device.
The device then enters Standby mode, raises pin INH, and transmits a wakeup message to the bus.
While transmitting the wakeup message to the bus, the device lowers pin HDO. After the transmission
is complete the device raises pin HDO. After the transmission is completed the device enters Normal
© 2007 Yamar Electronics Ltd.
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DS-ISL40 R1.6