ATA6613-EK Atmel, ATA6613-EK Datasheet - Page 8

• Manufacturer Part Number: ATA6613-EK
• Description: BOARD DEMO LIN-MCM FOR ATA6613
• Manufacturer: Atmel

Specifications of ATA6613-EK

• Main Purpose: Interface, LIN + MCU
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATA6613
• Primary Attributes: LIN-SBC (System-Basis-Chip) Transceiver, LIN 2.0, Voltage Regulator, Window Watchdog
• Secondary Attributes: 16 kB Flash, 4 Power Modes: Pre-Normal, Normal, Sleep, Silent, 48-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

3.1.4
3.1.4.1
3.1.4.2
3.1.4.3
3.1.4.4
8
ATA6612/ATA6613
LIN Interface (LIN, TXD and RXD)
LIN Pin
TXD Input/Output Pin (LIN SBC)
TXD Input/Output Pin (Microcontroller)
RXD Output Pin (LIN SBC)
The LIN Transceiver is only active when the LIN SBC is in the normal mode. In all other modes
the transceiver is switched off and no signals from the microcontroller will be transmitted on
the bus and no signals from the bus will be given to the microcontroller.
As the two pins TXD and RXD on the LIN SBC are controlled by the microcontroller’s UART,
they are connected to the corresponding TXD and RXD pins on the microcontroller via a zero
ohm resistor. For monitoring the signals at these pins, test points have been provided on the
development board.
A low-side driver with internal current limitation and thermal shutdown and an internal pull-up
resistor in compliance with LIN spec 2.0 are implemented. LIN receiver thresholds are com-
patible with the LIN protocol specification.
When using the development board for a LIN master application, it is possible to mount the
two necessary extra components diode D2 (e.g., LL4148) in series with resistor R1 (1 k ) on
the board at their designated placeholders.
The signals given to the TXD input pin control the state of the LIN output. The TXD input pin
must be pulled to ground in order to have the LIN bus low. If TXD is high, the LIN output tran-
sistor is turned off and the bus is in recessive state, pulled up by the internal/external resistor.
If TXD is low, the LIN output transistor is turned on and the bus is in dominant state. An inter-
nal timer prevents the bus line from being driven permanently in the dominant state. If TXD is
forced to low longer than t
high and the LIN bus driver is switched to the recessive state.
This feature is used to avoid that either a single faulty slave node or a short to ground at the
TXD pin can paralyze the communication on the complete LIN bus to which the faulty slave
node is connected. Due to this behavior, the internal state of the TXD pin can differ from the
signal level visible at the pin itself. However, if TXD is short-circuited to GND, it is possible to
switch to Sleep Mode via ENABLE after t
The TXD-pin from the microcontroller, belonging to the hardware UART, is hard-wired to the
TXD input pin from the LIN SBC via a 0 resistor.
As the LIN SBC indicates the wake-up source (local wake-up or remote wake-up) with the help
of the TXD pin it is recommended that the TXD pin from the microcontroller will be reconfig-
ured as an input when entering silent mode or sleep mode. As long as pin EN is still low after
a wake-up the LIN SBC signals the wake-up source on pin TXD.
This pin reports the state of the LIN bus to the microcontroller. LIN high (recessive state) is
reported by a high level at RXD; LIN low (dominant state) is reported by a low level at RXD.
The output has an internal pull-up structure with typically 5 k to VCC.
DOM_min
> 6 ms, the LIN SBC switches the TXD state internally to
DOM_max
> 20 ms.
9127A–AUTO–05/08