To avoid inadvertent watchdog configuration
changes the TCAN1469-Q1
implements a watchdog configuration register locking and unlocking mechanism. This
impacts registers 8'h13, 8'h14, 8'h16 and 8'h2D. These registers can only be programmed
in standby mode. The WD trigger write to 8'h15 automatically lock these registers. Once
these registers are locked, a SPI write to them is treated as a WD failure. To unlock
these registers, the device must transition into standby mode from normal or listen
mode, see
Figure 8-28. This unlock is good for one write to each of the registers.
Note: (1) Registers 8'h13, 8'h14,
8'h16, and 8'h2D are allowed one write each after entering standby mode before being
relocked.