Rainbow-electronics ATA6630 Instrukcja Użytkownika Pobierz pdf (Strona 15)

9117C–AUTO–10/09

ATA6628/ATA6630 [Preliminary]

4.5 Fail-safe Mode

The device automatically switches to Fail-safe Mode at system power-up. The voltage regulator

is switched on (V

= 3.3V/5V/2%/50 mA) (see Figure 5-1 on page 19). The NRES output

switches to low for t

res

= 4 ms and gives a reset to the microcontroller. LIN communication is

switched off. The IC stays in this mode until EN is switched to high. The IC then changes to Nor-

mal Mode. A power down of V

Batt

<VS

thU

) during Silent or Sleep Mode switches the IC 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 Table 4-3.

A wake-up event will lead the IC to the Fail-safe Mode.

Table 4-2. TXD, RXD Depending from Operation Modes

Different Modes TXD RXD

Fail-safe Mode Signalling fail-safe sources (see Table 4-3 and Table 4-4)

Normal Mode Follows data transmission

Silent Mode High High

Table 4-3. Signalling Fail-safe Sources

Fail-safe Sources TXD RXD

LIN wake-up (pin LIN) Low Low

Local wake-up (at pin Wake, pin KL15) Low High

(battery) undervoltage detection High Low

Table 4-4. Signalling in Fail-safe Mode after Reset (NRES was Low), Shows the Reset

Source at TXD and RXD Pins

Fail-safe Sources TXD RXD

VCC undervoltage at NRES High Low

Watchdog reset at NRES High High

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 33 34

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Rainbow-electronics ATA6630 Instrukcja Użytkownika Strona 15