Rainbow Electronics ATA6630 - Manual (Page 17)

17
9117C–AUTO–10/09
ATA6628/ATA6630 [Preliminary]
5. Wake-up Scenarios from Silent or Sleep Mode
5.1 Remote Wake-up via Dominant Bus State
A voltage less than the LIN Pre_Wake detection V
LINL
at the LIN pin activates the internal LIN
receiver and starts the wake-up detection timer.
A falling edge at the LIN pin followed by a dominant bus level V
BUSdom
maintained for a certain
time period (t
BUS
) and a rising edge at pin LIN result in a remote wake-up request. The device
switches from Silent or Sleep Mode to Fail-safe Mode. The VCC voltage regulator is/remains
activated, the INH pin is switched to high, and the internal slave termination resistor is switched
on. The remote wake-up request is indicated by a low level at the RXD pin to generate an inter-
rupt for the microcontroller and a strong pull down at TXD.
5.2 Local Wake-up via Pin WAKE
A falling edge at the WAKE pin followed by a low level maintained for a certain time period
(t
WAKE
) results in a local wake-up request. The device switches to Fail-safe Mode. The internal
slave termination resistor is switched on. The local wake-up request is indicated by a low level at
the TXD pin to generate an interrupt for the microcontroller. When the Wake pin is low, it is pos-
sible to switch to Silent or Sleep Mode via pin EN. In this case, the wake-up signal has to be
switched to high > 10 µs before the negative edge at WAKE starts a new local wake-up request.
5.3 Local Wake-up via Pin KL_15
A positive edge at pin KL_15 followed by a high voltage level for a certain time period (> t
KL_15
)
results in a local wake-up request. The device switches into the Fail-safe Mode. The internal
slave termination resistor is switched on. The extra long wake-up time ensures that no transients
at KL_15 create a wake-up. The local wake-up request is indicated by a low level at the TXD pin
to generate an interrupt for the microcontroller. During high-level voltage at pin KL_15, it is pos-
sible to switch to Silent or Sleep Mode via pin EN. In this case, the wake-up signal has to be
switched to low > 250 µs before the positive edge at KL_15 starts a new local wake-up request.
With external RC combination, the time is even longer.
5.4 Wake-up Source Recognition
The device can distinguish between different wake-up sources (see Table 4-4 on page 15 ).
The wake-up source can be read on the TXD and RXD pin in Fail-safe Mode. These flags are
immediately reset if the microcontroller sets the EN pin to high (see
Figure 4-3 on page 10 and
Figure 4-5 on page 12 ) and the IC is in Normal mode.