Chapter 17 LIN Physical Layer (S12LINPHYV2)MC9S12ZVMB Family Reference Manual Rev. 1.3566 NXP SemiconductorsPlease note that if the bit time is smaller than the parameter tOCLIM (please refer to electricals), then noovercurrent is reported nor does an overcurrent shutdown occur. However, the current limitation is alwaysengaged in case of a failure.17.4.3 ModesFigure 17-11 shows the possible mode transitions depending on control bits, stop mode, and errorconditions.17.4.3.1 Shutdown ModeThe LIN Physical Layer is fully disabled. No wake-up functionality is available. The internal pullupresistor is high ohmic only (330 k) to maintain the LIN Bus pin in the recessive state. LPTxD is notmonitored in this mode for a TxD-dominant timeout. All the registers are accessible.Setting LPE causes the module to leave the shutdown mode and to enter the normal mode or receive onlymode (if RXONLY bit is set).Clearing LPE causes the module to leave the normal or receive only modes and go back to shutdown mode.17.4.3.2 Normal ModeThe full functionality is available. Both receiver and transmitter are enabled. The internal pullup resistorcan be chosen to be high ohmic (330 k) if LPPUE = 0, or LIN compliant (34 k if LPPUE = 1.If RXONLY is set, the module leaves normal mode to enter receive only mode.If the MCU enters stop mode, the LIN Physical Layer enters standby mode.17.4.3.3 Receive Only ModeEntering this mode disables the transmitter and immediately stops any on-going transmission. LPTxD isnot monitored in this mode for a TxD-dominant timeout.The receiver is running in full performance mode in all cases.To return to normal mode, the RXONLY bit must be cleared.If the device enters stop mode, the module leaves receive only mode to enter standby mode.17.4.3.4 Standby Mode with Wake-Up FeatureThe transmitter of the LIN Physical Layer is disabled and the receiver enters a low power mode.NOTEBefore entering standby mode, ensure no transmissions are ongoing.If LPWUE is not set, no wake up feature is available and the standby mode has the same electricalproperties as the shutdown mode. This allows a low-power consumption of the device in stop mode if thewake-up feature is not needed.
