ZAMC4100GA2R datasheet(97/156 Pages) RENESAS

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ZAMC4100 Datasheet

January 26, 2016

LIN Short Protection

If there is a valid LIN short event, after the debounce time configured in the LINCTRL register (Table 3.46), the

LIN short interrupt is generated, and the LIN transmitter is disabled. This interrupt is indicated in the LINSHIF flag

bit in the LINSTAT register.

The ZAMC4100 detects a LIN short event if it is transmitting frames to a master device and the following

conditions are both met concurrently:

1) The current through the output stage of the LIN transmitter exceeds the value specified by the parameter

IOC_LIN (see Table 1.7).

2) The MCU transmits the dominant state, but the LIN bus remains in the recessive state.

LIN Dominant Time-Out Protection

If the dominant state at the LIN transmitter’s output continues more than 11ms, the logic detects this as a

dominant time-out event and consequently disables the LIN transmitter. The dominant time-out detection

generates an interrupt that is captured in the LINDTOIF flag of register LINSTAT. When LINDTOIF = HIGH, the

LIN transmitter is automatically powered-down. In this way, the dominant state caused by the ZAMC4100 is

isolated; i.e., the LIN bus is released and the other devices can continue to communicate.

Important Notes:

1. ZAMC4100 detects a LIN dominant time-out ONLY if it is caused by the device itself; i.e., due to an

internal error in the ZAMC4100 LIN transmitter path. If the LIN bus is forced into dominant state externally

(for more than 11ms), this is not a valid dominant time-out for the ZAMC4100 because it is not caused by

its transmitter stage. This prevents detection of a dominant time-out that is caused by another device on

the LIN bus, i.e. not by the ZAMC4100.

2. For robustness, the ZAMC4100 dominant time-out detection is implemented using both oscillators (OSCL

and OSCH), which ensures that this type of failure event will be detected even if one of the oscillators has

stopped.

3. The LIN dominant time-out detection feature is permanently enabled and cannot be disabled by software.

Table 3.46

LINCTRL Registers Bit Mapping

Name

LINCTRL

Bit No

Bit name

Reset

Access

R/W

Address

0x17

R/W = Read/Write bit

U = Unimplemented, read as ‘0’

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