The TCAN285x-Q1 family has three methods to reset the device. Two are
accomplished with SPI commands and are a soft reset and hard reset. Soft reset and
hard reset are accomplished by writing a 1b to DEVICE_RST register 8'h19[1] for soft
reset or to 8'h19[0] for hard reset.
Hard reset can also be performed by
pulling nRST low for tNRSTIN, see Figure 8-44.
When performing a soft reset,
the following takes place:
- Saved EEPROM registers are
reloaded
- All other registers are reset to
default values
- VCC1 and VCC2 do not change
state
- Device transitions to standby
mode
When performing a hard reset, the
following takes place:
- Device transitions to Init
mode
- Saved EEPROM registers are
reloaded
- All other registers are reset to
default values
- Most of the internal device logic
is reset to default
- VCC1 and VCC2 do not change
state
- Device then transitions to
restart mode and finally to standby mode where the device can be
reprogrammed
When pulling nRST pin low and releasing, the following takes place:
- Device transitions to Init
mode
- Saved EEPROM registers are
reloaded
- All other registers are reset to
default values
- Most of the internal logic is
reset to default
- VCC1 and VCC2 do not change
state
- Device then transitions to
restart mode and finally to standby mode where the device can be
reprogrammed
Note: The recommended is for any
changes to registers that are stored into EEPROM be saved to EEPROM. A reset causes
these registers to be loaded from EEPROM. This overwrites unsaved changes with the
last-saved register values from EEPROM.