JAJSNX3 February 2024 TCAN1465-Q1 , TCAN1469-Q1
ADVANCE INFORMATION
The TCAN1469-Q1 has an integrated watchdog function that supports three watchdog types; a window watchdog, a time-out watchdog, and a question and answer (Q&A) watchdog. These are highly configurable using the SPI pins for programming. This function is default disabled. When enabled, the watchdog timer does not start until the first input trigger event to register 8'h15 when in normal and standby (when enabled) operational modes. The watchdog timer is off in sleep mode. When in sleep mode the watchdog is disabled and requires the first watchdog trigger to start again once entering one of the allowed modes of operation. This is the same behavior when entering Fail-safe mode.
The INH pin can be used as a node reset by turning off the node power and turning it back on after 300ms. There are two programmable configuration for this function. This feature is enabled by configuring the WD_ACT bits in the WD_CONFIG1 register 8'h13[1:0], see Figure 8-26. The INH pin can be programmed as a LIMP function which provides a limp home capability when connected to external circuitry. Otherwise the nINT will reflect a watchdog failure and any specific programmed action. When in sleep mode, the limp pin is normally off, but if entered with it on, it will stay on. The LIMP pin turn off method can be programmed by using DEVICE_CONFIG1 register 8'h1A[3:2], LIMP_SEL_RESET. When the error counter reaches the watchdog trigger event level, the LIMP pin turns on connecting VSUP to the pin as described in the LIMP pin section. The watchdog flow chart Figure 8-27 provide the general flow for all three watchdog configurations and general behavior when LIMP pin is enabled instead of INH.