ZHCSPU9 February 2024 TCAN1465-Q1 , TCAN1469-Q1
ADVANCE INFORMATION
The sleep wake error (SWE) timer is a timer used to determine if specific external and internal functions are working and is disabled by default. Figure 8-23 provides an overview of when SWE timer is on and starts or off when fail-safe mode is enabled. This feature is enabled by setting 8'h1C[7] SWE_EN to 1b.
If enabled, when the device wakes up from a CAN bus WUP or a local wake standby mode is entered. Once in standby mode, the tSILENCE and tINACTIVE timers start. If tINACTIVE expires, the device re-enters sleep mode. When the device receives a CANINT, LWU or FRAME_OVF such that the device leaves sleep mode and enters standby mode, the processor has until tINACTIVE expires to clear the flags and place the device into normal mode. If this does not happen, the device enters sleep mode. When in standby, normal or listen mode and tSILENCE (SWE_EN=1b) or CANSLNT (SWE_DIS=0b) persists for tINACTIVE, the device enters sleep mode. Examples of events that can create this are the processor is no longer working and not able to exercise the SPI bus, a go to sleep command comes in and the processor is not able to receive the command or is not able to respond.
If the INH/LIMP pin for the TCAN1469-Q1 is configured as a LIMP pin, the tINACTIVE expiration causes the LIMP pin to assert and stay on until turned off by the processor.