ATA6630 ATMEL [ATMEL Corporation], ATA6630 Datasheet - Page 15

• Manufacturer Part Number: ATA6630
• Description: Negative Trigger Input for Watchdog
• Manufacturer: ATMEL [ATMEL Corporation]

4.5
9117E–AUTO–07/10
Fail-safe Mode
The device automatically switches to Fail-safe Mode at system power-up. The voltage regulator
is switched on (V
switches to low for t
switched off. The IC stays in this mode until EN is switched to high. The IC then changes to
Normal Mode. A power down of V
into Fail-safe Mode after power up. A low at NRES switches into Fail-safe Mode directly. During
Fail-safe Mode, the TXD pin is an output and signals the fail-safe source. The watchdog is
switched on.
The LIN SBC can operate in different Modes, like Normal, Silent, or Sleep Mode. The functional-
ity of these modes is described in
Table 4-2.
A wake-up event from either Silent or Sleep Mode will be signalled to the microcontroller using
the two pins RXD and TXD. The coding is shown in
A wake-up event will lead the IC to the Fail-safe Mode.
Table 4-3.
Table 4-4.
Different Modes
Fail-safe Mode
Normal Mode
Silent Mode
Fail-safe Sources
LIN wake-up (pin LIN)
Local wake-up (at pin Wake, pin KL15)
VS
Fail-safe Sources
VCC undervoltage at NRES
Watchdog reset at NRES
th
(battery) undervoltage detection
TXD, RXD Depending from Operation Modes
Signalling Fail-safe Sources
Signalling in Fail-safe Mode after Reset (NRES was Low), Shows the Reset
Source at TXD and RXD Pins
CC
res
= 3.3V/5V/2%/50 mA) (see
= 4 ms and gives a reset to the microcontroller. LIN communication is
ATA6628/ATA6630 [Preliminary]
Table
Batt
(V
Signalling fail-safe sources (see
S
4-2.
< VS
High
TXD
thU
) during Silent or Sleep Mode switches the IC
Figure 5-1 on page
Table
Follows data transmission
TXD
High
High
TXD
High
Low
Low
4-3.
Table 4-3
19). The NRES output
and
RXD
High
Table
RXD
High
RXD
High
Low
Low
Low
4-4)
15