Datasheet
23
AT30TSE752A/754A/758A [DATASHEET]
Atmel-8854G-DTS-AT30TSE752A-754A-758A-Datasheet_102014
6.4 Nonvolatile Configuration Register
The Nonvolatile Configuration Register is a 16-bit wide Read/Write Register used to manage key power-up/reset device
settings and operational modes including the locking of the AT30TSE752A/754A/758A's various registers. The
Nonvolatile Configuration Register is used in conjunction with the Configuration Register to control how the device
operates. All bits in the Nonvolatile Configuration Register will retain their state even after the device has been powered
down or reset. On every power up or reset sequence, the contents of the most-significant byte (bits 15 through 8) of the
Nonvolatile Configuration Register will be copied into the Configuration Register, after which all device operations and
settings will then be controlled by the Configuration Register. By utilizing the Nonvolatile Configuration Register, the
device can power-up or reset in a pre-defined, user-selected operating mode (e.g. Comparator mode, Shutdown mode,
etc.) with pre-defined settings (e.g. 12-bit resolution, ALERT pin active high, etc.). Therefore, unlike standard LM75-type
temperature sensors, there is no need to update the Configuration Register settings after every power-up or reset.
Since the Nonvolatile Configuration Register utilizes nonvolatile storage cells, care must be taken when updating the
register to accommodate the aspects of an associated program time and finite program endurance limit. Power must not
be removed from the device during the internally self-timed programming cycle of the register. If power is removed prior
to the completion of the programming cycle, then the contents of the register cannot be guaranteed. In addition, the
contents of the register may become corrupt if it is programmed more than the maximum allowed number of writes.
Table 6-8. Nonvolatile Configuration Register
Bit Name Type Description
15 NU Not Used R 0 Not used
14:13 NVR1:NVR0 Conversion Resolution R/W
00 9-bits (Factory Default)
01 10-bits
10 11-bits
11 12-bits
12:11 NVFT1:NVFT0 Fault Tolerance Queue R/W
00 Alarm after 1 Fault (Factory Default)
01 Alarm after 2 Consecutive Faults
10 Alarm after 4 Consecutive Faults
11 Alarm after 6 Consecutive Faults
10 NVPOL ALERT Pin Polarity R/W
0 ALERT Pin is Active Low (Factory Default)
1 ALERT Pin is Active High
9 NVCMP/INT Alarm Thermostat Mode R/W
0 Comparator Mode (Factory Default)
1 Interrupt Mode
8 NVSD Shutdown Mode R/W
0
Temperature Sensor Performing Active Measurements
(Factory Default)
1
Temperature Sensor Disabled and Device in Shutdown
mode
7:3 RFU Reserved for Future Use 0 Reserved for Future Use
2 RLCKDWN Register Lockdown R/W
0
All Configuration and Limit Registers are not locked down
(Factory Default).
1
All Configuration and Limit Registers are permanently
locked down (ROM) and can never be modified again.
1 RLCK Register Lock R/W
0
All Configuration and limit registers are unlocked and can
be modified (Factory Default).
1
All Configuration and Limit Registers are locked and
cannot be modified.
0 RFU Reserved for Future Use R 0 Reserved for Future Use